Abstract: Stannic chloride is protected with polystyrene-divinylbenzene (7%) copolyme beads in CS₂ to form a stable complex containing 10.8% of chlorine. The SnCl₄ supported by the polystyrene is resistant to water and is Prolonged Storing in air at least one year. The complex catalyst (PS-SnCl₄) is a strong solid Lewis acid. The Lewis acid supported by polymer can be used to catalyze a lot of organic synthetic reactions in high yield, such as esterfications, acetal formations, ketal formations, etherifications and Friedel-Crafts alkylations.