Methylchlorophenyldichlorosilane (MeClPhSiCl 2 ) and methyldichlorophenyldichlorosilane (MeCl 2 PhSiCl 2 ) were synthesized by the catalytic chlorination of methylphenyldichlorosilane (MePhSiCl 2 ) with Cl 2 over Lewis acid catalysts. The catalytic activities of Lewis acid catalysts were in an order of FeCl 3 >SbCl 5 >AlCl 3 >SnCl 4 . However, FeCl 3 also highly catalyzed the cleavage of chlorophenyl–silicon bond to form chlorobenzene. At a low mole ratio of SbCl 5 to MePhSiCl 2 of 1.4×10 −5 :0.45, the yield of MeClPhSiCl 2 was around 60% after reacting at 25–100°C for 15–20h. At a high mole ratio of 1.4×10 −4 :0.45, the yield of MeCl 2 PhSiCl 2 reached 44% after reacting at 80–100°C for 20h.