Doped with Sb and Te, Mg2Si based compounds were prepared respectively by solid state reaction at 823K for 8h, Effects of dopants of Sb and Te on the strcuture and thermoelectric properties of the compounds were investigated. By calculating the values of the electrical conductivity for Sb-doped sample, the mecha-nism of electric conduction at 625K is different, The figure of merit for sample doped with 0.4wt% Te at 500K is 2.4×10-3W/mK2, and it reaches 3.3×10-3W/mK2 at 650K for the sample doped with 0.5wt% Sb. The values are more than 1.4 times and 2.3 times of the pure Mg2Si sample.