A method of controlling uplink transmission power, by a user equipment, in a wireless communication system, the method comprising: receiving a signal on a downlink channel in dual connectivity with master eNB and secondary eNB, wherein the signal includes information on transmission power which indicates a power control mode for whether the master eNB and the secondary eNB are synchronous or asynchronous; allocating transmission power for a sounding reference signal of the master eNB and transmission power for a sounding reference signal of the secondary eNB depending on whether the master eNB and the secondary eNB are synchronous or asynchronous; transmitting the sounding reference signal of the master eNB to the master eNB based on the allocated transmission power for the sounding reference signal of the master eNB; transmitting the sounding reference signal of the secondary eNB to the secondary eNB based on the allocated transmission power for the sounding reference signal of the secondary eNB, wherein when the master eNB and the secondary eNB are asynchronous, subframe i and subframe i+1 of the master eNB overlap with subframe j of the secondary eNB, and the method further comprises allocating a portion of a total transmission power at a last symbol of the subframe i to the transmission power for the sounding reference signal of the master eNB, the last symbol in the subframe i is immediately preceding a specific boundary, and allocating a portion of the total transmission power at a symbol in the subframe j to the transmission power for the sounding reference signal of the secondary eNB, the symbol in the subframe j being immediately following the specific boundary, and the specific boundary corresponds to a boundary between the subframe i and the subframe i+1; wherein when the master eNB and the secondary eNB are synchronous, the method further comprises allocating transmission power for channel of channel state information of the secondary eNB and wherein the transmission power for the sounding reference signal of the master eNB and the transmission power for the sounding reference signal of the secondary eNB are allocated with lower priority than the transmission power for the channel state information of the secondary eNB. receiving a signal on a downlink channel in dual connectivity with master eNB and secondary eNB, wherein the signal includes information on transmission power which indicates a power control mode for whether the master eNB and the secondary eNB are synchronous or asynchronous; allocating transmission power for a sounding reference signal of the master eNB and transmission power for a sounding reference signal of the secondary eNB depending on whether the master eNB and the secondary eNB are synchronous or asynchronous; transmitting the sounding reference signal of the master eNB to the master eNB based on the allocated transmission power for the sounding reference signal of the master eNB; transmitting the sounding reference signal of the secondary eNB to the secondary eNB based on the allocated transmission power for the sounding reference signal of the secondary eNB, wherein when the master eNB and the secondary eNB are asynchronous, subframe i and subframe i+1 of the master eNB overlap with subframe j of the secondary eNB, and the method further comprises allocating a portion of a total transmission power at a last symbol of the subframe i to the transmission power for the sounding reference signal of the master eNB, the last symbol in the subframe i is immediately preceding a specific boundary, and allocating a portion of the total transmission power at a symbol in the subframe j to the transmission power for the sounding reference signal of the secondary eNB, the symbol in the subframe j being immediately following the specific boundary, and the specific boundary corresponds to a boundary between the subframe i and the subframe i+1; wherein when the master eNB and the secondary eNB are synchronous, the method further comprises allocating transmission power for channel of channel state information of the secondary eNB and wherein the transmission power for the sounding reference signal of the master eNB and the transmission power for the sounding reference signal of the secondary eNB are allocated with lower priority than the transmission power for the channel state information of the secondary eNB.