Abstract: Cobalt complex of N, N′-bis(salicylidene) propane-1,3-diamine (Co(Salprn)) was encapsulated in the supercages of zeolite Y by the flexible ligand method. The encapsulated sample Co(Salprn)-Y was characterized by X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, infrared spectroscopy as well as differential-thermal analysis techniques. Its catalytic performance for the epoxidation of alkenes was investigated. The results indicted that the encapsulation does not have strong influence on the framework structure of zeolitic host and Co(Salprn)-Y prepared exhibits much higher catalytic activity than the neat Co(Salprn) complex in the epoxidation of styrene. The catalytic performance of Co(Salprn)-Y is affected significantly by the reaction conditions. Moreover, Co(Salprn)-Y is also catalytically active for the epoxidation of a variety of other alkenes; its activity decreases in the order of styrene > cyclohexene > cyclooctene > 1-octene.