Hi All, One doubt is not clear yet, gone through the documentation also. As I already mentioned my directory structure in "Clustering on WLS5.1". First I started my adminServer on port 7777 after this I am trying to start Cluster Server on Port 8888. While starting adminServer at Port 7777 dont have any problem after this when I starting ClusterServer giving the Exception Port 7777 is already in use, it is not going to read weblogic.property file in the weblogic_install_dir\mycluster\server1\weblogic.properties where I defined ListenPort is 8888 . My command line argument is like this for startServer1.sh .... java -ms64m -mx64m \ ... ... -Dweblogic.system.name=weblogic_install_dir\mycluster\server1 -Dweblogic.cluster.name=weblogic_install_dir\mycluster -Dweblogic.cluster.enable=true \ And for adminServer java -ms64m -mx64m \ ... ... -Dweblogic.system.name=weblogic_install_dir\mycluster -Dweblogic.cluster.name=weblogic_install_dir\mycluster -Dweblogic.cluster.enable=true \ I am not sure about this configuration, esp -Dweblogic.system.name and -Dweblogic.cluster.name value. One more doubt what are all the resources that is going to be in the weblogic_install_dir\mycluster\server1 directory currently I have just weblogic.property file only. Please share your idea. Thanks Hong