Tetramethyl orthosilicate (TMOS) was obtained by the direct synthesis of methanol with metallic silicon including copper compound as a catalyst and zinc compound as a promoter. The effects of the preheating temperature and the preparation method of the contact mass on TMOS synthesis were investigated. The composition effects of the contact mass which was composed of metallic silicon with copper catalyst and various metallic halide promoters including Zn, Sn or Cd compound were studied also. The best performance on TMOS synthesis was observed on the mixed bed reactor containing metallic silicon preheated with CuCl as a catalyst and ZnCl₂ as a promoter. When Cu/Si = 7 wt%, Zn/Cu = 7 wt% was mixed in a slurry phase and activated into contact mass at 380℃, the average selectivity was 87.2% in the silicon consumption of 69.2% at 220℃.