The high figure of merit and earth abundance of Cu12Sb4S13 thermoelectric ma- terials have recently attracted many attentions toward these type of complex compounds. Intrinsic low thermal conductivity, as well as tunable electronic transport properties, make them suitable for thermoelectric power generation. In this study, we perform a comparative theoretical study on the substituted compounds, primarily at the Cu site including known tetrahedrite Cu12Sb4S13, by means of first-principles calculations. The density functional theory of electric structure is applied to investigate the result of substitution.