A method performed by a first base station in which a Master Cell Group, MCG, is configured in a wireless communication system, the method comprising: receiving, from a user equipment, UE, secondary cell group, SCG, failure information associated with a SCG; transmitting, to a second base station in which the SCG is configured, a first secondary node modification request message; receiving, from the second base station, a secondary node modification acknowledge message; and transmitting, to the UE, a first radio resource control, RRC, connection reconfiguration message including configuration information for a measurement of the UE for SCG resume, wherein the first secondary node modification request message includes the SCG failure information including a SCG failure cause; wherein the method further comprises: receiving, from the UE, a measurement report based on the configuration information for the measurement; transmitting, to the second base station, a second secondary node modification request message including information on candidate cell list and a measurement result based on the measurement report; receiving, from the second base station, a message including information on a target cell associated with the SCG resume with the UE; and transmitting, to the UE, a second RRC connection reconfiguration message including information on a removal of the measurement. receiving, from a user equipment, UE, secondary cell group, SCG, failure information associated with a SCG; transmitting, to a second base station in which the SCG is configured, a first secondary node modification request message; receiving, from the second base station, a secondary node modification acknowledge message; and transmitting, to the UE, a first radio resource control, RRC, connection reconfiguration message including configuration information for a measurement of the UE for SCG resume, wherein the first secondary node modification request message includes the SCG failure information including a SCG failure cause; wherein the method further comprises: receiving, from the UE, a measurement report based on the configuration information for the measurement; transmitting, to the second base station, a second secondary node modification request message including information on candidate cell list and a measurement result based on the measurement report; receiving, from the second base station, a message including information on a target cell associated with the SCG resume with the UE; and transmitting, to the UE, a second RRC connection reconfiguration message including information on a removal of the measurement. receiving, from the UE, a measurement report based on the configuration information for the measurement; transmitting, to the second base station, a second secondary node modification request message including information on candidate cell list and a measurement result based on the measurement report; receiving, from the second base station, a message including information on a target cell associated with the SCG resume with the UE; and transmitting, to the UE, a second RRC connection reconfiguration message including information on a removal of the measurement.