The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-Generation (4G) communication system such as long term evolution (LTE). The method for operating a primary base station in a wireless communication system is provided. The method includes transmitting, to a secondary base station, an addition request message, wherein the addition request message carries information of a secondary cell group (SCG) split bearer; and receiving, from the secondary base station, a response message of the addition request message.