maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
               enableLookups=
"false" redirectPort="8443" acceptCount="100"
               connectionTimeout=
"20000" disableUploadTimeout="true" />

*found xwiki's config file web.xml,change encoding charset from iso-8859-1 to UTF-8.appling this change to 
xwiki.cfg,velocity.properties too.

*and source codes: 
D:\dev\xwiki\trunk\core\src\main\java\com\xpn\xwiki\web>svn diff Utils.java
Index: Utils.java
===================================================================

--- Utils.java  （修订版 1748）
+++ Utils.java  （工作拷贝）
@@ -393,18 +393,28 @@
         }
     }

+    public static String FixUtf8(String str)
+    {
+        try {
+            byte b[]=str.getBytes
("ISO-8859-1");
+            int lp=b.length;
+            while(--lp>=0 && b[lp]>=0) {};
+        if(lp>=0) return new String(b,"UTF-8");
+        }
+        catch(Exception e)

+        {
+        }
+        return str;
+    }
+
     public static String decode(String name, XWikiContext context) {
         try {
             // Make sure + is considered as a space
             String result = 
name.replace('+', ' ');
-
+            String ret=URLDecoder.decode(result, context.getWiki().getEncoding(
));
             // It seems Internet Explorer can send us back UTF-8
             // instead of ISO-8859-1 for URLs

-            if (Base64.isValidUTF8(result.getBytes(), false))
-                result = new String(result.getBytes(), "UTF-8");
-
-            // Still need to decode URLs
-            return URLDecoder.decode
(result, context.getWiki().getEncoding());
+            return   FixUtf8(ret);
         } catch (Exception e) {
             return name;
         }

D:\dev\xwiki\trunk\core\src\main\java\com\xpn\xwiki\web>svn diff 
XWikiServletRequest.java
Index: XWikiServletRequest.java
===================================================================
--- XWikiServletRequest.java    （修订版 1748）
+++ XWikiServletRequest.java    （工作拷贝）

@@ -88,7 +88,7 @@
     }

     public String getPathInfo() {
-        return request.getPathInfo();
+        return Utils.FixUtf8(request.getPathInfo());
     }

     public String getPathTranslated() {



* Thanks Michael for give us detailed method to export utf-8 document as pdf(http://mail-archive.objectweb.org/xwiki-dev/2006-03/msg00030.html
). I use this command to get info of charset:
java -cp fop-0.20.5.jar org.apache.fop.fonts.apps.TTFReader -ttcname "SimSun"  D:\MYFONTS\simsun.ttc simsun.xml
