1. A method performed by an user equipment (UE) for requesting scheduling for an uplink data transmission in a wireless communication system, the method comprising:receiving additional scheduling request (SR) resource configuration information including additional SR resource information and buffer size information configured to an additional SR resource in addition to a default SR resource from a base station;
transmitting an SR through the default SR resource or the additional SR resource to the base station;
receiving, from the base station, uplink resource allocation information which is determined according to the resource in which the SR is transmitted by the user equipment; and
transmitting, by the user equipment, uplink data to the base station through a physical uplink shared channel (PUSCH) resource which is allocated by the uplink resource allocation information,
wherein the SR is transmitted to the base station through the additional SR resource, if an uplink data size is same as or smaller than a buffer size.