Provided is a method for reporting a buffer state by a user equipment accessing a first eNB and a second eNB in a communication system, the method comprising the steps of: triggering a buffer state report for new data when the new data is generated; selecting at least one eNB to which the buffer state report is to be transmitted, on the basis of the amount of uplink data to be transmitted; transmitting the buffer state report for the new data to the selected at least one eNB; receiving, from at least one eNB among the first eNB and the second eNB, a resource allocated by the at least one eNB as a response to the buffer state report; and transmitting the new data using the allocated resource.