Provided are a method for controlling uplink transmission power and a wireless device. The wireless device decides a first transmission power of a first uplink channel, which is transmitted through a first wireless resource from a first serving cell, and decides a second transmission power of a second uplink channel, which is transmitted through a second wireless resource from a second serving cell. The first serving cell belongs to a first timing advance (TA) group, and the second serving cell belongs to a second TA group that differs from the first TA group. All or a portion of the first wireless resource and the second wireless resource overlap, wherein the sum of the first and second transmission powers in the overlapping portion is decided so as not to exceed a maximum transmission power.