Abstract: Hierarchical ZSM-11 zeolites with different SiO2/Al2O3 and different crystal size were used as active components of cracking catalysts and compared with commercial cracking catalysts (ZSM-5 as an active component). These active components were characterized by means of XRD, SEM, N2 adsorption, NH3-TPD and FT-IR. The results indicate that ZSM-11 zeolites possess pure crystal phase with high crystallinity, special intergrowth morphology as well as hierarchical pore structure. When tested in a micro fixed-bed reactor using Fushun vacuum gas oil (VGO) as a feedstock, catalysts based on ZSM-11 exhibit both better conversion ability for heavy oil and higher selectivity to high-value products (C3=+C4= and light fractions) than ZSM-5 catalyst. Particularly, the ZSM-11 sample with SiO2/Al2O3 ratio of 50 shows the superior performance than the other samples. In addition, as the crystal size decreases to 200 nm, the catalyst presents both enhanced conversion ability and selectivity to light oil but lower selectivity to light olefins.