Abstract：Ratio of Lewis／Br~nsted acid sites(CYCb)on the surface of nanosized HZSM一5 was successfully manipulated by means of steami ng and acid leaching． Significant enhancement of the deactivation durability of nanosized HZSM一5 in the aromatization of fluid catalytic cracking(FCC) gasoline olefins seems to be closely related to the increase of Lewis／Br0nsted acid sites ratio． 便攜式車載氣相色譜儀