N-hexane and gasoline fraction conversion on bismuthchromezeolite catalyst at 300-500°C was researched. It was showed that in cataly sate total content of izomerization products reduce. The maximum content of aromatic hydrocarbons is 16.5% at 450°C and minimum benzene formation (0.8%). Ennoblement of gasoline fraction on bismuthchromezeolite catalyst contributes increase octane number on 29 points at 400°C. Benzene content is 1.4% that accord with environmental requirements of motor fuels.