;In recent years, alternative and green energy has been a trend due to energy exhaust and environmental awareness. Thus, thermoelectricity has attracted the attentions. Thermoelectric material can create electromotive force under given temperature difference and perform exothermic and endothermic reaction under given electric current. What really differentiates thermoelectric transformation depends on the materials figure of merit (ZT). Therefore, the enhancement of the material’s ZT value is an important topic. Mg2(Si,Sn) is a promising thermoelectric material for high performance power generator. Magnesium, silicon, tin bismuth and Mn5Si3 nanopowders were prepared and pressed into bulk materials for different temperatures and annealing prcesses to form the alloy.A thermoelectric module is fabricated and measured to prove its thermoelectric characteristics. A maximum output power (13.2μW) is achieved.