Powerful plastics was made by the copolymerization of methyl metacrylate with allyl silicate. Allyl silicate (CH3) Si (O-CH2-CH=CH2) 3, (CH3) 2Si (O-CH2-CH=CH2) 2, (CH3) 3SiO-CH2-CH=CH2) as crossrinking agent was prepared by the reaction of methyl chlorosilane with allyl alcohol. Allyl silicate obtained by this reaction is a new kind of compound. Only allyl silicate did not polymerization using benzoyl peroxide catalyst, but the copolymerization of allyl silicate with methyl metacrylate results in polymers containing only small amount of allyl silicate. With methyl metacrylate only about few mole per cent of allyl silicate was found in the copolymer. Wheres allylsilicate is completely unreactive toward this compound give extensive reaction. The allyl silicate methyl metacrylate copolymers are hard, brittle resin, insoluble in either, aceton etc.