The present invention relates to a wireless communication system. More particularly, the present invention relates to a method and an apparatus for a terminal controlling uplink power in a carrier aggregation-based wireless communication system, comprising the steps of: configuring a first cell and a second cell; transmitting a first PUCCH signal from subframe #n in the first cell; and transmitting a second PUCCH signal from subframe #n in the second cell, wherein when the sum of transmit power of the first PUCCH signal and transmit power of the second PUCCHJ signal exceeds a predetermined maximum transmit power configured to the terminal, the transmit power of the PUCCH signal having a lower priority from among the first UCCH signal and the second PUCCH signal is reduced or the transmission is dropped.