Mn substitution compounds YCo1?x Mnx O3 (0≤x≤0.2) are synthesized by using the sol–gel process. Electrical transport properties of YCo1?x Mnx O3 are investigated in the temperature range from 200 K to 780 K. The experimental results show that after Mn substitution the electrical resistivity of YCo1?x Mnx O3 first increases, then decreases, which is due to the electrons introduced by Mn doping. The sign of Seebeck coefficient for YCo1?x Mnx O3 (x 6=0) is positive or negative, which is also proved by the Hall coefficient measurement. Moreover, at about room temperature, the Seebeck coefficient of YCo1?x Mnx O3 with 1%doping Mn content becomes a negative value, whose absolute value is maximum;furthermore, the absolute value gradually decreases with increasing the Mn substitution content, which can be explained by the double carrier model.