diff --git a/src/main/java/com/sunyard/util/DnUtil.java b/src/main/java/com/sunyard/util/DnUtil.java
index 1c237af..17efe39 100644
--- a/src/main/java/com/sunyard/util/DnUtil.java
+++ b/src/main/java/com/sunyard/util/DnUtil.java
@@ -7,37 +7,40 @@ public class DnUtil {
 
 
     public static LinkedHashMap<String, String> dnToMap(String dn) {
-        LinkedHashMap<String, String>map = new LinkedHashMap<String, String>();
+        LinkedHashMap<String, String> map = new LinkedHashMap<String, String>();
         String[] kvs = dn.split(",");
-        for ( String kv : kvs ) {
+        for (String kv : kvs) {
             String[] ps = kv.split("=");
-            map.put( ps[0].trim() , ps[1].trim() );
+            map.put(ps[0].trim(), ps[1].trim());
         }
         return map;
     }
 
-    public static String verifyDn( String dn ) {
-        if ( dn.startsWith("C=") || dn.startsWith("c=")) {
-            return dn;
-        }
-        // 反转顺序
-        String[] kvs = dn.split(",");
-        StringBuilder sb = new StringBuilder();
-
-        for ( String kv : kvs ) {
-
-            if ( sb.length() > 0 ) {
-                sb.insert(0, ",");
+    public static String verifyDn(String dn) {
+        if ( "true".equals(System.getProperty("com.sunyard.dnsort", "true"))) {
+            if (dn.startsWith("C=") || dn.startsWith("c=")) {
+                return dn;
             }
-            sb.insert(0,  kv );
+            // 反转顺序
+            String[] kvs = dn.split(",");
+            StringBuilder sb = new StringBuilder();
+
+            for (String kv : kvs) {
+
+                if (sb.length() > 0) {
+                    sb.insert(0, ",");
+                }
+                sb.insert(0, kv);
 
 //            if ( sb.length() > 0 ) {
 //                sb.append(",");
 //            }
 //            sb.append( key + "=" + map.get( key ) );
-        }
+            }
 
-        return sb.toString();
+            return sb.toString();
+        }
+        else return dn;
     }
 
 }
diff --git a/src/main/java/racal/sunyard/main/SydApi4j.java b/src/main/java/racal/sunyard/main/SydApi4j.java
index cd23e34..ab4902f 100644
--- a/src/main/java/racal/sunyard/main/SydApi4j.java
+++ b/src/main/java/racal/sunyard/main/SydApi4j.java
@@ -46,6 +46,8 @@ import java.security.cert.X509Certificate;
 import java.text.SimpleDateFormat;
 import java.util.*;
 
+import static com.sunyard.util.DnUtil.verifyDn;
+
 public class SydApi4j implements SydApi {
 
     static {
@@ -775,7 +777,7 @@ public class SydApi4j implements SydApi {
         byte[] dn = new byte[256];
         byte[] s = null;
         try {
-            sCertDN = DnUtil.verifyDn(sCertDN);
+            sCertDN = verifyDn(sCertDN);
             s = sCertDN.getBytes("GBK");
         } catch (UnsupportedEncodingException e) {
             e.printStackTrace();
@@ -1094,7 +1096,7 @@ public class SydApi4j implements SydApi {
         byte[] dn = new byte[256];
         byte[] s = null;
         try {
-            sCertDN = DnUtil.verifyDn(sCertDN);
+            sCertDN = verifyDn(sCertDN);
             s = sCertDN.getBytes("GBK");
         } catch (UnsupportedEncodingException e) {
             e.printStackTrace();
@@ -2848,7 +2850,7 @@ public class SydApi4j implements SydApi {
 
     public RetWrap generateDEByDnHsm(String certSerial, byte[] oData) {
 
-        certSerial = DnUtil.verifyDn(certSerial);
+        certSerial = verifyDn(certSerial);
 
         byte[] dnBytes = null;
         try {
@@ -2861,7 +2863,7 @@ public class SydApi4j implements SydApi {
 
     public RetWrap generateDEByDnHsmRSA(int alg, String certSerial, byte[] oData) {
 
-        certSerial = DnUtil.verifyDn(certSerial);
+        certSerial = verifyDn(certSerial);
 
         byte[] dnBytes = null;
         try {
@@ -2988,7 +2990,7 @@ public class SydApi4j implements SydApi {
 
     public RetWrap decryptDEByDNHsm(String certSerial, String pCipherKey) {
 
-        certSerial = DnUtil.verifyDn(certSerial);
+        certSerial = verifyDn(certSerial);
 
         byte[] dnBytes = null;
         try {
@@ -3001,7 +3003,7 @@ public class SydApi4j implements SydApi {
 
     public RetWrap decryptDEByDNHsmRSA(String certSerial, String pCipherKey) {
 
-        certSerial = DnUtil.verifyDn(certSerial);
+        certSerial = verifyDn(certSerial);
 
         byte[] dnBytes = null;
         try {
@@ -3022,7 +3024,8 @@ public class SydApi4j implements SydApi {
     public String getCertByDn(String dn) throws UnsupportedEncodingException {
         byte[] dnBytes = null;
         try {
-            dnBytes = dn.getBytes("gbk");
+            String dnsort = verifyDn(dn);
+            dnBytes = dnsort.getBytes("gbk");
         } catch (UnsupportedEncodingException e) {
             e.printStackTrace();
             throw e;
@@ -3094,7 +3097,7 @@ public class SydApi4j implements SydApi {
 
     public RetWrap generateDEByDnSoft(String certSerial, byte[] oData) {
 
-        certSerial = DnUtil.verifyDn(certSerial);
+        certSerial = verifyDn(certSerial);
 
         RetWrap ret = new RetWrap();
         byte[] dnBytes = null;
@@ -3158,7 +3161,7 @@ public class SydApi4j implements SydApi {
 
     public RetWrap generateDEByDnSoftRSA(int alg, String certSerial, byte[] oData) {
 
-        certSerial = DnUtil.verifyDn(certSerial);
+        certSerial = verifyDn(certSerial);
 
         RetWrap ret = new RetWrap();
         byte[] dnBytes = null;
@@ -3351,7 +3354,7 @@ public class SydApi4j implements SydApi {
 
     public RetWrap decryptDEByDNSoft(String certSerial, String pCipherKey) {
 
-        certSerial = DnUtil.verifyDn(certSerial);
+        certSerial = verifyDn(certSerial);
 
         byte[] dnBytes = null;
         try {
@@ -3390,7 +3393,7 @@ public class SydApi4j implements SydApi {
 
     public RetWrap decryptDEByDNSoftRSA(String certSerial, String pCipherKey) {
 
-        certSerial = DnUtil.verifyDn(certSerial);
+        certSerial = verifyDn(certSerial);
 
         byte[] dnBytes = null;
         try {
@@ -11500,7 +11503,7 @@ public class SydApi4j implements SydApi {
     }
 
     public String attachedSignSoft(byte[] orgData, String sCertDN) throws UnsupportedEncodingException {
-        sCertDN = DnUtil.verifyDn(sCertDN);
+        sCertDN = verifyDn(sCertDN);
         String pk = this.GetDNPublicKey(SydApi.FOR_SIGN, sCertDN.getBytes("GBK"));
         try {
             byte[] hash = this.SM3Hash(pk, orgData);
@@ -11618,7 +11621,7 @@ public class SydApi4j implements SydApi {
 
 
     public String attachedSignRSASoft(int rFlag,byte[] orgData, String sCertDN) throws UnsupportedEncodingException {
-        sCertDN = DnUtil.verifyDn( sCertDN );
+        sCertDN = verifyDn( sCertDN );
         try {
             RetWrap hashData = countHash(0, 0, orgData, null);
             byte[] hash = (byte[]) hashData.get("hash");
@@ -11631,7 +11634,7 @@ public class SydApi4j implements SydApi {
     }
 
     public String attachedSignRSAHsm(int rFlag,byte[] orgData, String sCertDN) {
-        sCertDN = DnUtil.verifyDn( sCertDN );
+        sCertDN = verifyDn( sCertDN );
 
         Proto8018 proto = new Proto8018();
         byte[] dn = new byte[256];
@@ -11693,7 +11696,7 @@ public class SydApi4j implements SydApi {
 
 
     public String attachedSignHsm(byte[] orgData, String sCertDN) {
-        sCertDN = DnUtil.verifyDn( sCertDN );
+        sCertDN = verifyDn( sCertDN );
 
         Proto8018 proto = new Proto8018();
         byte[] dn = new byte[256];
diff --git a/src/test/java/sample/Shanghairenhang.java b/src/test/java/sample/Shanghairenhang.java
index 3dd7d4d..43feadf 100644
--- a/src/test/java/sample/Shanghairenhang.java
+++ b/src/test/java/sample/Shanghairenhang.java
@@ -91,5 +91,12 @@ public class Shanghairenhang {
         byte[] bytes = api.SYD_NakedSign(orgData2k, pcDnEN);
         System.out.println(Util.bytes2HexString(bytes));
     }
+    @Test
+    public void aboutCert(){
+        //System.setProperty("com.sunyard.sydapi4j.debug", "true");
+        SydApiBuilder builder = new SydApiBuilder().setIp("192.168.0.200");
+        SydApi4j api = (SydApi4j) builder.build();
+
+    }
 
 }
\ No newline at end of file