1. A method for keeping, by a user equipment (UE), a first dual connectivity (DC) configuration in a wireless communication system, the method comprising:receiving, from a network, information for validation of a DC configuration, wherein the DC configuration includes the first DC configuration and a second DC configuration;
determining whether or not the first DC configuration is valid in a radio resource control (RRC) resume procedure, based on the information for validation of the DC configuration;
based on the first DC configuration that is valid, keeping the first DC configuration in an RRC resume procedure;
releasing the second DC configuration before initiating the RRC resume procedure; and
transmitting, to the network, a message for RRC resume request which includes information regarding whether or not the first DC configuration is kept.