A method and apparatus for controlling power of a transmitter in a mesh network. A controller, if it sets a reference power to one of a first measured transmission power and a maximum power, compares the reference power with a first power in level, and compares the first power with a second power in level. A cumulation factor calculator calculates a cumulation factor by comparing the first power with the second power. A reference power setter sets the reference power according to a scope to which a value obtained by adding a reference power to a sum of the calculated cumulation factors belongs. A power controller controls transmission power according to the set reference power.