diff --git a/maker/csharp/DbMaker/DbMaker.cs b/maker/csharp/DbMaker/DbMaker.cs
new file mode 100644
index 0000000..43fefbf
--- /dev/null
+++ b/maker/csharp/DbMaker/DbMaker.cs
@@ -0,0 +1,423 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Text;
+using DbMaker;
+
+namespace DbMaker
+{
+
+/**
+ * fast ip db maker
+ * 
+ * db struct:
+ * 1. header part
+ * 1): super part:
+ * +------------+-----------+
+ * | 4 bytes	| 4 bytes   |
+ * +------------+-----------+
+ *  start index ptr, end index ptr
+ * 
+ * 2): b-tree index part
+ * +------------+-----------+-----------+-----------+
+ * | 4bytes		| 4bytes	| 4bytes	| 4bytes	| ...
+ * +------------+-----------+-----------+-----------+
+ *  start ip ptr  index ptr
+ *  
+ * 2. data part:
+ * +------------+-----------------------+
+ * | 2bytes		| dynamic length		|
+ * +------------+-----------------------+
+ *  data length   city_id|Country|Province|Area|City|ISP
+ *  
+ * 3. index part: (ip range)
+ * +------------+-----------+---------------+
+ * | 4bytes		| 4bytes	| 4bytes		|
+ * +------------+-----------+---------------+
+ *  start ip 	  end ip	  3 byte data ptr & 1 byte data length
+ * 
+ * @author chenxin<chenxin619315@gmail.com>
+*/
+public class DbMaker 
+{	
+	/**
+	 * db config 
+	*/
+	private DbConfig dbConfig;
+	
+	/**
+	 * ip source file path
+	*/
+	private FileStream ipSrcFile;
+	
+	/**
+	 * buffer 
+	*/
+	private List<IndexBlock>  indexPool;
+	private List<HeaderBlock> headerPool;
+	
+	/**
+	 * global region Id mapping data 
+	*/
+	private FileStream globalRegionFile = null;
+	private Dictionary<String, int> globalRegionMap = null;
+	
+	/**
+	 * region and data ptr mapping data 
+	*/
+	private Dictionary<String, DataBlock> regionPtrPool = null;
+	
+	/**
+	 * construct method
+	 * 
+	 * @param	config
+	 * @param	ipSrcFile tb source ip file
+	 * @param	globalRegionFile global_region.csv file offer by lion
+	 * @throws	DbMakerConfigException 
+	 * @throws	IOException 
+	*/
+	public DbMaker( 
+			DbConfig config, 
+			String ipSrcFile, 
+			String globalRegionFile )
+	{
+		this.dbConfig = config;
+		this.ipSrcFile = File.OpenRead(ipSrcFile); //new File(ipSrcFile);
+		this.globalRegionMap = new Dictionary<string, int>(); //new HashMap<String, Integer>();
+		this.regionPtrPool = new Dictionary<string, DataBlock>(); //new HashMap<String, DataBlock>();
+		if ( globalRegionFile != null )
+		{
+			this.globalRegionFile = File.OpenRead(globalRegionFile); //new File(globalRegionFile);
+		}
+		
+		//if ( this.ipSrcFile.exists() == false ) {
+		if (!File.Exists(ipSrcFile))
+		{
+			throw new IOException("Error: Invalid file path " + ipSrcFile);
+		}
+	}
+	
+	/**
+	 * initialize the db file 
+	 * 
+	 * @param	raf
+	 * @throws IOException 
+	*/
+	private void initDbFile( RandomAccessFile raf )
+	{
+		//1. zero fill the header part
+		raf.seek(0L);
+		raf.write(new byte[8]);		//super block
+		raf.write(new byte[dbConfig.getTotalHeaderSize()]);		//header block
+		
+		headerPool = new List<HeaderBlock>(); //new LinkedList<HeaderBlock>();
+		indexPool  = new List<IndexBlock>(); //new LinkedList<IndexBlock>();
+	}
+	
+	/**
+	 * make the Db file 
+	 * 
+	 * @param	dbFile target output file path
+	 * @throws IOException 
+	*/
+	public void make(String dbFile) 
+	{
+		//check and load the gloabl region
+		if ( globalRegionFile != null ) {
+			Console.WriteLine("+-Try to load the global region data ...");
+			StreamReader greader = new StreamReader((globalRegionFile));
+			String gline = null;
+			while (!greader.EndOfStream ) {
+				gline = greader.ReadLine();// != null 
+				if (String.IsNullOrWhiteSpace(gline))
+				{
+					continue;
+				}
+				
+				String[] p = gline.Split(",");
+				if ( p.Length != 5 ) continue;
+				
+				//push the mapping
+				globalRegionMap.put(p[2], Int32.Parse(p[0]));
+			}
+			
+			greader.Close();
+			Console.WriteLine("|--[Ok]");
+		}
+		
+		//alloc the header size
+		StreamReader reader = new StreamReader(this.ipSrcFile);
+		RandomAccessFile raf  = new RandomAccessFile(dbFile);
+		
+		//init the db file
+		initDbFile(raf);
+		Console.WriteLine("+-Db file initialized.");
+		
+		//analysis main loop
+		Console.WriteLine("+-Try to write the data blocks ... ");
+		String line = null;
+		while ( !reader.EndOfStream ) {
+			//line = reader.ReadLine()
+			line = reader.ReadLine();
+			if (String.IsNullOrWhiteSpace(line))
+			{
+				continue;
+			}
+			line = line.Trim();
+			if ( line.Length == 0 ) 	 continue;
+			if ( line[0] == '#' ) continue;
+			
+			//1. get the start ip
+			int sIdx = 0, eIdx = 0;
+			if ( (eIdx = line.IndexOf('|', sIdx + 1)) == -1 ) continue;
+			String startIp = line.Substring(sIdx, eIdx);
+			
+			//2. get the end ip
+			sIdx = eIdx + 1;
+			if ( (eIdx = line.IndexOf('|', sIdx + 1)) == -1 ) continue;
+			String endIp = line.Substring(sIdx, eIdx);
+			
+			//3. get the region
+			sIdx = eIdx + 1;
+			String region = line.Substring(sIdx);
+			
+			Console.WriteLine("+-Try to process item " + line);
+			addDataBlock(raf, startIp, endIp, region);
+			Console.WriteLine("|--[Ok]");
+		}
+		Console.WriteLine("|--Data block flushed!");
+		Console.WriteLine("|--Data file pointer: "+raf.getFilePointer()+"\n");
+		
+		//write the index bytes
+		Console.WriteLine("+-Try to write index blocks ... ");
+		
+		//record the start block
+		IndexBlock indexBlock = null;
+		HeaderBlock hb = null;
+		indexBlock = indexPool.First();
+		long indexStartIp = indexBlock.getStartIp(), 
+					indexStratPtr = raf.getFilePointer(), indexEndPtr;
+		headerPool.add(new HeaderBlock(indexStartIp, (int)(indexStratPtr)));
+		
+		int blockLength = IndexBlock.getIndexBlockLength();
+		int counter = 0, shotCounter = (dbConfig.getIndexBlockSize()/blockLength) - 1;
+		//Iterator<IndexBlock> indexIt = indexPool.iterator();
+		//while ( indexIt.hasNext() ) {
+		foreach(var block in indexPool){
+			if ( ++counter >= shotCounter ) {
+				hb = new HeaderBlock(
+					block.getStartIp(),
+					(int)raf.getFilePointer()
+				);
+				
+				headerPool.add(hb);
+				counter = 0;
+			}
+			
+			//write the buffer
+			raf.write(block.getBytes());
+		}
+		
+		//record the end block
+		if ( counter > 0 ) {
+			indexBlock = indexPool.Last();
+			hb = new HeaderBlock(
+				indexBlock.getStartIp(),
+				((int)raf.getFilePointer()) - IndexBlock.getIndexBlockLength()
+			);
+			
+			headerPool.add(hb);
+		}
+		
+		indexEndPtr = raf.getFilePointer();
+		Console.WriteLine("|--[Ok]");
+		
+		//write the super blocks
+		Console.WriteLine("+-Try to write the super blocks ... ");
+		raf.seek(0L);	//reset the file pointer
+		byte[] superBuffer = new byte[8];
+		Util.writeIntLong(superBuffer, 0, indexStratPtr);
+		Util.writeIntLong(superBuffer, 4, indexEndPtr - blockLength);
+		raf.write(superBuffer);
+		Console.WriteLine("|--[Ok]");
+		
+		//write the header blocks
+		Console.WriteLine("+-Try to write the header blocks ... ");
+		//Iterator<HeaderBlock> headerIt = headerPool.iterator();
+		//while ( headerIt.hasNext() ) {
+		//	HeaderBlock headerBlock = headerIt.next();
+		//	raf.write(headerBlock.getBytes());
+		//}
+		foreach (var headerBlock in headerPool)
+		{
+			raf.write(headerBlock.getBytes());
+		}
+		
+		//write the copyright and the release timestamp info
+		Console.WriteLine("+-Try to write the copyright and release date info ... ");
+		raf.seek(raf.length());
+		//Calendar cal = Calendar.getInstance();
+		//SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd");
+		var date = DateTime.Now;
+		String copyright = "Created by lionsoul at " + date.ToString("yyyy/MM/dd");
+var timespan=		new DateTimeOffset(date).ToUnixTimeSeconds();
+		raf.write((int)(timespan));	//the unix timestamp
+		raf.write(copyright.getBytes("UTF-8"));
+		Console.WriteLine("|--[Ok]");
+		
+		reader.Close();
+		raf.close();
+	}
+	
+	/**
+	 * internal method to add a new data block record
+	 * 
+	 * @param	raf
+	 * @param	startIp
+	 * @param	endIp
+	 * @param	region data
+	*/
+	private void addDataBlock(
+			RandomAccessFile raf, 
+			String startIp, String endIp, String region)
+	{
+		
+		byte[] data = region.getBytes("UTF-8");
+		int dataPtr = 0;
+		    
+		/*byte[] city = new byte[4];
+        int city_id = getCityId(region);
+        Util.writeIntLong(city, 0, city_id);
+        dataPtr = (int)raf.getFilePointer();
+        raf.write(city);
+        raf.write(data);*/
+            
+		//check region ptr pool first
+		if ( regionPtrPool.containsKey(region) ) {
+			DataBlock dataBlock = regionPtrPool.get(region);
+			dataPtr = dataBlock.getDataPtr();
+			Console.WriteLine("dataPtr: " + dataPtr + ", region: " + region);
+		} else {
+			byte[] city = new byte[4];
+			int city_id = getCityId(region);
+			Util.writeIntLong(city, 0, city_id);
+			dataPtr = (int)raf.getFilePointer();
+			raf.write(city);
+			raf.write(data);
+                
+			regionPtrPool.put(region, new DataBlock(city_id, region, dataPtr));
+		}
+			
+		//add the data index blocks
+		IndexBlock ib = new IndexBlock(
+			Util.ip2long(startIp), 
+			Util.ip2long(endIp), 
+			dataPtr,
+			data.Length + 4		//4 bytes for the city id
+		);
+		indexPool.add(ib);
+	}
+	
+	/**
+	 * get the city id base on the global region data 
+	 * 
+	 * @param	region
+	 * @return	int
+	*/
+	public int getCityId( String region )
+	{
+		String[] p = region.Split("\\|");
+		if ( p.Length != 5 ) return 0;
+		
+		String key = null;
+		int? intv = null;
+		for ( int i = 3; i >= 0; i-- ) {
+			if ( p[i].Equals("0") ) continue;
+			if ( i == 3 
+				&& p[i].IndexOf("省直辖县级") > -1 ) {
+				key = p[2]+p[3];
+			} else {
+				key = p[i];
+			}
+			
+			intv = globalRegionMap.get(key);
+			if ( intv == null ) return 0;
+			return intv.Value;
+		}
+		
+		return 0;
+	}
+	
+	public DbConfig getDbConfig()
+	{
+		return dbConfig;
+	}
+
+	public DbMaker setDbConfig(DbConfig dbConfig)
+	{
+		this.dbConfig = dbConfig;
+		return this;
+	}
+
+	public FileStream getIpSrcFile()
+	{
+		return ipSrcFile;
+	}
+
+	public DbMaker setIpSrcFile(FileStream ipSrcFile)
+	{
+		this.ipSrcFile = ipSrcFile;
+		return this;
+	}
+	
+	/**
+	 * make this directly a runnable application
+	 * interface to make the database file 
+	*/
+	public static void Main(String[] args)
+	{
+	    String dstDir = "./data/";
+	    String[] path = new String[]{null, null};
+	    for ( int i = 0; i < args.Length; i++ ) {
+	        if ( args[i].Equals("-src") ) {
+	            path[0] = args[++i];
+	        } else if ( args[i].Equals("-region") ) {
+	            path[1] = args[++i];
+	        } else if ( args[i].Equals("-dst") ) {
+	            dstDir  = args[++i];
+	        }
+	    }
+	    
+	    for ( int i = 0; i < path.Length; i++ ) {
+	        if ( path[i] == null ) {
+	            Console.WriteLine("Usage: java -jar dbMaker.jar "
+	                    + "-src [source text file path] "
+	                    + "-region [global region file path]");
+	            Console.WriteLine("eg: java -jar dbMaker.jar "
+	                    + "-src ./data/ip.merge.txt -region ./data/origin/global_region.csv");
+	            //System.exit(0);
+	            Environment.Exit(0);
+	        }
+	    }
+	    
+	    //check and stdlize the destination directory
+	    if ( ! dstDir.EndsWith("/") ) {
+	        dstDir = dstDir + "/";
+	    }
+	    
+	    try {
+            DbConfig config = new DbConfig();
+            DbMaker dbMaker = new DbMaker(config, path[0], path[1]);
+            dbMaker.make(dstDir + "ip2region.db");
+        } catch (DbMakerConfigException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        } catch (IOException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
+	}
+}
+}
\ No newline at end of file
diff --git a/maker/csharp/DbMaker/Extensions.cs b/maker/csharp/DbMaker/Extensions.cs
new file mode 100644
index 0000000..1976903
--- /dev/null
+++ b/maker/csharp/DbMaker/Extensions.cs
@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace DbMaker
+{
+    public static class Extensions
+    {
+        public static byte[] getBytes(this string str, string encode)
+        {
+            return Encoding.GetEncoding(encode).GetBytes(str);
+        }
+
+        public static Boolean containsKey<TKey, TValue>(this IDictionary<TKey, TValue> dic, TKey key)
+        {
+            return dic.ContainsKey(key);
+        }
+
+        public static TValue get<TKey, TValue>(this IDictionary<TKey, TValue> dic, TKey key)
+        {
+            return dic[key];
+        }
+
+        public static void put<TKey, TValue>(this IDictionary<TKey, TValue> dic, TKey key, TValue value)
+        {
+            dic.Add(key,value);
+        }
+
+        public static void add<TItem>(this IList<TItem> list, TItem item)
+        {
+            list.Add(item);
+        }
+
+        public static void printStackTrace(this Exception e)
+        {
+            Console.WriteLine(e);
+        }
+    }
+}
\ No newline at end of file
diff --git a/maker/csharp/DbMaker/Program.cs b/maker/csharp/DbMaker/Program.cs
deleted file mode 100644
index c2072e3..0000000
--- a/maker/csharp/DbMaker/Program.cs
+++ /dev/null
@@ -1,12 +0,0 @@
-using System;
-
-namespace DbMaker
-{
-    class Program
-    {
-        static void Main(string[] args)
-        {
-            Console.WriteLine("Hello World!");
-        }
-    }
-}
\ No newline at end of file
diff --git a/maker/csharp/DbMaker/RandomAccessFile.cs b/maker/csharp/DbMaker/RandomAccessFile.cs
index 71ca6c2..d9f5031 100644
--- a/maker/csharp/DbMaker/RandomAccessFile.cs
+++ b/maker/csharp/DbMaker/RandomAccessFile.cs
@@ -45,5 +45,20 @@ namespace DbMaker
         {
             _stream.Dispose();
         }
+
+        public void write(byte[] bytes)
+        {
+            _stream.Write(bytes);
+        }
+
+        public void write(int i)
+        {
+            
+        }
+
+        public long getFilePointer()
+        {
+            return _stream.Position;
+        }
     }
 }
\ No newline at end of file