Polystyrene (PS) has been chemically modified with cyclic anhydrides such as glutaric anhydride (GA), citraconic anhydride (CA) and phthalic anhydride (PA) in the presence of BF 3 .O(C 2 H 5 ) 2 in chloroform and succinic anhydride (SA) in 1,2-dichloroethane. Some important reaction parameters were determined in order to optimize the acylation process. ATR FT- IR and 1 H NMR studies indicate that the acylation reaction can introduce both carboxyl group and double bond (for only citraconic anhydride) onto pendant aromatic groups of the polymer. The adhesion properties and corrosion resistance of the acylated PS on metal surface under various conditions have been investigated.