CuIn0.7Ga0.3Se2 (CIGS) was synthesized using Cu, In, Ga and Se powders as starting materials by self-propagating high-temperature synthesis method (SHS). The phase and crystallographic structure，chemical composition of the products were characterized by X-ray Diffraction, X-ray Photoelectron Spectroscopy, Energy Dispersive X-ray spectrometer and Laser Raman Spectroscopy. The results show different factors in this process such as reactant ratio, atmosphere pressure etc. obviously influence the stoichiometric composition of the products. An accurate stoichiometric, single-phase chalcopyrite-type CIGS can be prepared by SHS.