Amorphous SiO2-Al2O3 was prepared by solgel method and cobalt oxide supported on SiO2-Al2O3 was prepared by impregnation method. These materials were characterized by BET, XRD, TPD and FT-IR. The activity of SiO2-Al2O3 and Co3O4/SiO2-Al2O3 catalysts for nitrosation of cyclohexane with nitrosyl sulfuric acid in the presence of fuming sulphuric acid was evaluated. The results indicate that SiO2- Al2O3 and Co3O4/SiO2-Al2O3 can catalyze efficiently this nitrosation reaction. And Co3O4/SiO2-Al2O3 gave better results with 11.93% of conversion and 54.68% of selectivity to e-caprolactam. This discovery establishes a potential method for one-pot synthesis of e-caprolactam from cyclohexane. It may be of potential application prospect and of prominent theoretical significance.