diff --git a/binding/csharp/IP2Region.SearchTest/Program.cs b/binding/csharp/IP2Region.SearchTest/Program.cs
index 35267f2..eca95c0 100644
--- a/binding/csharp/IP2Region.SearchTest/Program.cs
+++ b/binding/csharp/IP2Region.SearchTest/Program.cs
@@ -1,10 +1,7 @@
 using IP2Region.xdb;
 using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+using System.IO;
 
 namespace IP2Region.SearchTest
 {
@@ -65,7 +62,7 @@ namespace IP2Region.SearchTest
 
                 String key = r.Substring(2, sIdx - 2);
                 String val = r.Substring(sIdx + 1);
-                // System.out.printf("key=%s, val=%s\n", key, val);
+                // Console.WriteLinef("key=%s, val=%s\n", key, val);
                 if ("db" == key)
                 {
                     dbPath = val;
@@ -83,7 +80,7 @@ namespace IP2Region.SearchTest
 
             if (dbPath.Length < 1)
             {
-                Console.WriteLine("jSearchTest.exe search [command options]");
+                Console.WriteLine("SearchTest.exe search [command options]");
                 Console.WriteLine("options:");
                 Console.WriteLine(" --db string              ip2region binary xdb file path");
                 Console.WriteLine(" --cache-policy string    cache policy: file/vectorIndex/content");
@@ -118,7 +115,117 @@ namespace IP2Region.SearchTest
         }
         public static void BenchTest(String[] args)
         {
+            String dbPath = "", srcPath = "", cachePolicy = "vectorIndex";
+            foreach (String r in args)
+            {
+                if (r.Length < 5)
+                {
+                    continue;
+                }
 
+                if (r.IndexOf("--") != 0)
+                {
+                    continue;
+                }
+
+                int sIdx = r.IndexOf('=');
+                if (sIdx < 0)
+                {
+                    Console.WriteLine("missing = for args pair `{0}`", r);
+                    return;
+                }
+
+                String key = r.Substring(2, sIdx - 2);
+                String val = r.Substring(sIdx + 1);
+                if ("db" == key)
+                {
+                    dbPath = val;
+                }
+                else if ("src" == key)
+                {
+                    srcPath = val;
+                }
+                else if ("cache-policy" == key)
+                {
+                    cachePolicy = val;
+                }
+                else
+                {
+                    Console.WriteLine("undefined option `{0}`", r);
+                    return;
+                }
+            }
+
+            if (dbPath.Length < 1 || srcPath.Length < 1)
+            {
+                Console.WriteLine("SearchTest.exe bench [command options]");
+                Console.WriteLine("options:");
+                Console.WriteLine(" --db string              ip2region binary xdb file path");
+                Console.WriteLine(" --src string             source ip text file path");
+                Console.WriteLine(" --cache-policy string    cache policy: file/vectorIndex/content");
+                return;
+            }
+
+            Searcher searcher = CreateSearcher(dbPath, cachePolicy);
+            long count = 0;
+            var sw = new Stopwatch();
+            var lines = File.ReadAllLines(srcPath);
+            foreach (var line in lines)
+            {
+                String l = line.Trim();
+                String[] ps = l.Split(new[] { '|' }, 3);
+                if (ps.Length != 3)
+                {
+                    Console.WriteLine("invalid ip segment `{0}`", l);
+                    return;
+                }
+                long sip;
+                try
+                {
+                    sip = Searcher.checkIP(ps[0]);
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine("check start ip `{0}`: {1}", ps[0], e);
+                    return;
+                }
+                long eip;
+                try
+                {
+                    eip = Searcher.checkIP(ps[1]);
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine("check end ip `{0}`: {1}", ps[1], e);
+                    return;
+                }
+
+                if (sip > eip)
+                {
+                    Console.WriteLine("start ip({0}) should not be greater than end ip({1})", ps[0], ps[1]);
+                    return;
+                }
+
+                long mip = (sip + eip) >> 1;
+                foreach (var ip in new long[] { sip, (sip + mip) >> 1, mip, (mip + eip) >> 1, eip })
+                {
+                    sw.Start();
+                    String region = searcher.Search(ip);
+                    sw.Stop();
+                    // check the region info
+                    if (ps[2] != (region))
+                    {
+                        Console.WriteLine("failed search({0}) with ({1} != {2})\n", Searcher.Long2ip(ip), region, ps[2]);
+                        return;
+                    }
+
+                    count++;
+                }
+            }
+
+            Console.WriteLine("Bench finished, {{cachePolicy: {0}, total: {1}, took: {2}, cost: {3} ms/op}}",
+                    cachePolicy, count, sw.Elapsed,
+                    count == 0 ? 0 : sw.ElapsedMilliseconds / count);
         }
         static void Main(string[] args)
         {