Abstract: A curable chlorinated polyethylene and copolyethylene composition comprising(A) 5 to 95% by weight, based on the total weight of (A) and (B), of a chlorinated polyethylene having a chlorine content of about 20 to about 50% by weight and derived from polyethylene having a melt index of 0.01 to 100,(B) 95 to 5% by weight, based on the total weight of (A) and (B), of a chlorinated copolymer of ethylene and a C.sub.2 -C.sub.5 alkyl acrylate or methacrylate, said copolymer having a chlorine content of about 2 to about 45% by weight and a melt index of 0.1 to 100,(C) 0 to 30 parts by weight, per 100 parts by weight of (A) and (B) combined, of an epichlorohydrin polymer or copolymer at least 40 mole % of which is derived from the epichlorohydrin, said polymer or copolymer having a specific reduced viscosity of 0.1 to 10 dl/g,(D) 0.1 to 5 parts by weight, per 100 parts by weight of (A), (B) and (C) combined, of a mercaptotriazine compound as a crosslinking agent,(E) 0.