A method and an apparatus for configuring uplink transmission power and apparatus in a mobile communication system supporting downlink and uplink carrier aggregation are provided. The method includes determining a per-terminal maximum transmission power and per-serving cell maximum transmission powers based on ΔTC,c as a value for allowing an adjustment of additional transmission power for multiple serving cells, Maximum Power Reductionc (MPRc) as a value determined according to an amount of transmission resources allocated to the terminal, and Additive-MPRc (A-MPRc) as a value determined according to local characteristics and frequency band characteristics, determining per-serving cell uplink transmission powers by restricting required transmission powers for respective serving cells to the corresponding per-serving cell maximum transmission powers, comparing a sum of the per-serving cell uplink transmission powers with the per-terminal maximum transmission power, and adjusting the per-serving cell uplink transmission powers according to comparison result.