The conversion of methanol to hydrocarbons has been studied over synthetic ZSM-5 zeolite catalyst having high silica to alumina ratio. The conversion products were olefins, paraffins, cycloparaffins, and aromatics, and the catalyst showed especially high selectivity toward the formation of aromatics. The catalyst showed the shape-selectivity and the size of molecules in the product was limited approximately to the size of 1,3,5-trimethylbenzene. Hydrogen form(HZSM-5) was more active, indicating reactions following the dehydration of methanol seemed to be mainly catalyzed by acid sites. Comparison of the reaction characteristics and acid site distribution of the ZSM-5 catalyst with those of mordenite and faujasite type catalysts suggests that cross-linked pore channel structure and the strong acidity of the ZSM-5 catalyst are primarily responsible for the selective formation of aromatics over this catalyst.