Abstarct: The subject of this thesis is due to synthesis of shciffbaxse molybdenum catalytic systems PVC-Schiff baxse –[MoO2(acac)] , PVC-EN-Schiff baxse-Mo(CO)4 , PVC-EA-[MoO2(acac)] that were immobilized onto poly vinyl chloride as support. The catalytic activity of this catalyst were studied. At first, molybdenum Schiff baxse compounds were immobilized to poly vinyl chloride via covalantly bonds and then this immobilized catalysts were well characterized by spectroscopic techiques.This catalyst was found as an efficient catalyst for epoxidation of alkens. The effect of reaction parameters such as solvent and oxidant were investigated. At the present of this catalyst, carbon tetrachloride as a solvent and tert-butyl hydroperoxide(TBHP) as oxidizing agent were employed.This system was used as an efficient catalyst for other alken epoxidation with TBHP in CCl4 as solvent. The results indicated high catalytic activity in alken epoxidation. The heterogeneous catalyst can be reused several times without significant loss of its catalytic activity.