Abstract: The methanol conversion over HY zeolite was studied at 1atm, 280℃~360℃. The effects of temperature, GHSV, and reaction time on the performance of reaction of methanol were discussed. The results showed that HY catalyst gave isoalkanes with high selectivity. Higher temperature(280℃~340℃) and lower GHSV decreased the selectivity to dimethyl ether and increased that to C2，C3，i-C4 ，i-C5. With the further increase of temperature, the selectivity of C2，C3 increased while that to i-C4 ，i-C5 decreased. The selectivity to isoalkanes decreased quickly with the reaction time.