diff --git a/shadowsocks-go.sh b/shadowsocks-go.sh
index 585f2ef..a83a6f1 100644
--- a/shadowsocks-go.sh
+++ b/shadowsocks-go.sh
@@ -10,14 +10,14 @@ export PATH
 #==================================================================
 
 clear
-echo ""
+echo
 echo "#############################################################"
 echo "# One click Install Shadowsocks-go server                   #"
 echo "# Intro: https://teddysun.com/392.html                      #"
 echo "# Author: Teddysun <i@teddysun.com>                         #"
 echo "# Thanks: @cyfdecyf <https://twitter.com/cyfdecyf>          #"
 echo "#############################################################"
-echo ""
+echo
 
 # Make sure only root can run our script
 function rootness(){
@@ -68,7 +68,7 @@ function is_64bit(){
         return 0
     else
         return 1
-    fi        
+    fi
 }
 
 # Disable selinux
@@ -85,11 +85,11 @@ function pre_install(){
     echo "Please input password for shadowsocks-go:"
     read -p "(Default password: teddysun.com):" shadowsockspwd
     [ -z "$shadowsockspwd" ] && shadowsockspwd="teddysun.com"
-    echo ""
+    echo
     echo "---------------------------"
     echo "password = $shadowsockspwd"
     echo "---------------------------"
-    echo ""
+    echo
     # Set shadowsocks-go config port
     while true
     do
@@ -99,11 +99,11 @@ function pre_install(){
     expr $shadowsocksport + 0 &>/dev/null
     if [ $? -eq 0 ]; then
         if [ $shadowsocksport -ge 1 ] && [ $shadowsocksport -le 65535 ]; then
-            echo ""
+            echo
             echo "---------------------------"
             echo "port = $shadowsocksport"
             echo "---------------------------"
-            echo ""
+            echo
             break
         else
             echo "Input error! Please input correct numbers."
@@ -121,7 +121,7 @@ function pre_install(){
         stty echo
         stty $SAVEDSTTY
     }
-    echo ""
+    echo
     echo "Press any key to start...or Press Ctrl+C to cancel"
     char=`get_char`
     #Install necessary dependencies
@@ -138,7 +138,7 @@ function pre_install(){
         IP=$(curl -s -4 ipinfo.io/ip)
     fi
     echo -e "Your main public IP is\t\033[32m$IP\033[0m"
-    echo ""
+    echo
     #Current folder
     cur_dir=`pwd`
 }
@@ -205,23 +205,43 @@ function config_shadowsocks(){
 EOF
 }
 
-# iptables set
-function iptables_set(){
-    echo "iptables start setting..."
-    /sbin/service iptables status 1>/dev/null 2>&1
-    if [ $? -eq 0 ]; then
-        /sbin/iptables -L -n | grep '${shadowsocksport}' | grep 'ACCEPT' >/dev/null 2>&1
-        if [ $? -ne 0 ]; then
-            /sbin/iptables -I INPUT -m state --state NEW -m tcp -p tcp --dport ${shadowsocksport} -j ACCEPT
-            /sbin/iptables -I INPUT -m state --state NEW -m udp -p udp --dport ${shadowsocksport} -j ACCEPT
-            /etc/init.d/iptables save
-            /etc/init.d/iptables restart
+# firewall set
+function firewall_set(){
+    echo "firewall set start..."
+    if centosversion 6; then
+        /etc/init.d/iptables status > /dev/null 2>&1
+        if [ $? -eq 0 ]; then
+            iptables -L -n | grep '${shadowsocksport}' | grep 'ACCEPT' > /dev/null 2>&1
+            if [ $? -ne 0 ]; then
+                iptables -I INPUT -m state --state NEW -m tcp -p tcp --dport ${shadowsocksport} -j ACCEPT
+                iptables -I INPUT -m state --state NEW -m udp -p udp --dport ${shadowsocksport} -j ACCEPT
+                /etc/init.d/iptables save
+                /etc/init.d/iptables restart
+            else
+                echo "port ${shadowsocksport} has been set up."
+            fi
         else
-            echo "port ${shadowsocksport} has been set up."
+            echo "WARNING: iptables looks like shutdown or not installed, please manually set it if necessary."
+        fi
+    elif centosversion 7; then
+        systemctl status firewalld > /dev/null 2>&1
+        if [ $? -eq 0 ];then
+            firewall-cmd --permanent --zone=public --add-port=${shadowsocksport}/tcp
+            firewall-cmd --permanent --zone=public --add-port=${shadowsocksport}/udp
+            firewall-cmd --reload
+        else
+            echo "Firewalld looks like not running, try to start..."
+            systemctl start firewalld
+            if [ $? -eq 0 ];then
+                firewall-cmd --permanent --zone=public --add-port=${shadowsocksport}/tcp
+                firewall-cmd --permanent --zone=public --add-port=${shadowsocksport}/udp
+                firewall-cmd --reload
+            else
+                echo "WARNING: Try to start firewalld failed. please enable port ${shadowsocksport} manually if necessary."
+            fi
         fi
-    else
-        echo "iptables looks like shutdown, please manually set it if necessary."
     fi
+    echo "firewall set completed..."
 }
 
 # Install 
@@ -247,23 +267,23 @@ function install_go(){
             echo "Shadowsocks-go start failure!"
         fi
     else
-        echo ""
+        echo
         echo "shadowsocks-go install failed!"
         exit 1
     fi
     cd $cur_dir
     clear
-    echo ""
+    echo
     echo "Congratulations, shadowsocks-go install completed!"
     echo -e "Your Server IP: \033[41;37m ${IP} \033[0m"
     echo -e "Your Server Port: \033[41;37m ${shadowsocksport} \033[0m"
     echo -e "Your Password: \033[41;37m ${shadowsockspwd} \033[0m"
     echo -e "Your Local Port: \033[41;37m 1080 \033[0m"
     echo -e "Your Encryption Method: \033[41;37m aes-256-cfb \033[0m"
-    echo ""
+    echo
     echo "Welcome to visit:https://teddysun.com/392.html"
     echo "Enjoy it!"
-    echo ""
+    echo
     exit 0
 }
 
@@ -307,9 +327,7 @@ function install_shadowsocks_go(){
     config_shadowsocks
     install_go
     if [ "$OS" == 'CentOS' ]; then
-        if centosversion 6; then
-            iptables_set
-        fi
+        firewall_set
     fi
 }
 
@@ -327,4 +345,4 @@ uninstall)
     echo "Arguments error! [${action} ]"
     echo "Usage: `basename $0` {install|uninstall}"
     ;;
-esac
\ No newline at end of file
+esac