Controlled tuning the electrical characteristics of the semiconducting materials is one of the primary technological challenges of thermoelectricity. Here, we demonstrate that high temperatures is greatly influence on the Seebeck coefficient and conductivity. We investigated the thermoelectric power (Seebeck coefficient) of p!type semiconductors with the general formula (GeSe)(CuAsSe) (at x = 0.1, 0.2, 0.3 and 0.6) at high temperatures from 300 to 1-х2х 400 K. We found high Seebeck coefficient and electrical conductivity which increase sharply with increasing temperature Thus, our work has uncovered a new face of (GeSe)(CuAsSe) 1-х2х as a new thermoelectric material.