A method for communicating between serving general packet radio service support nodes SGSN, adapting to the mobile communication network which coexists multiple SGSN supporting different IP protocol version, that characterizes in, in advance configuring for SGSN with IP address of all IP protocol version supported by itself, when source SGSN initiates communication to target SGSN, first detecting IP protocol version supported by target SGSN, then based on the detected result, communicating with target SGSN using IP protocol version supported by source/target. The invention can implement mutually communicating between SGSN supporting the different IP protocol version, improving compatibility of network.