Conversion of chloromethane to olefins over SAPO-34 and HZSM-22 catalysts has been investigated at various temperatures. SAPO-34 showed higher activity and better stability than HZSM-22 catalyst. Ethylene and propylene were the main products over SAPO-34, whereas the main products over HZSM-22 were propylene, butylene, and C5+ alkanes in this conversion. Polymethylated benzenes and methylnaphthalene were the main components of coke species confined in the spent SAPO-34 catalyst. However, long-chain alkanes were the main species trapped in the spent HZSM-22 catalyst in the initial period, and many polymethylated benzenes emerged with growing time on stream. The differences in selectivity and coke species from both spent catalysts suggested that the conversion of chloromethane to olefins was greatly influenced by the topology structure of zeolite catalyst and that olefin methylation and cracking might be an important route followed over the HZSM-22 catalyst.