For a long year as viscous additives to lubricating oils polymers and copolymers of vinyl monomers, mainly, isobutylene and acrylmethacrylates were used. The abovementioned compounds have high polymerization ability and at synthesis of viscous additives are obtained so named “defect” or “weak” connections in the compounds. Physics of polymeric compounds at the same time with their molecular mass is defined the arrangement of monomeric links in polymeric chain. In the synthesis of viscous additives side by side with vinyl monomers allyl monomere used. Allyl monomers separately do not polymerize but they used at the synthesis of polymeric compounds by alternation of monomeric links. As allyl monomers o-allylphenol and allyl esters of high carbonic acids were used. The above – mentioned compounds were undergoing to daible copolymerization with styrene and high alkylmethacrylates in the presence of initiator radical polymerization. The influence on the process of composition of the mixture of monomers, temperature, consumption of initiator and duration of copolymerization was investigated. At the same time copolymers containing 50% links of allyl monomers with the yield 80-93% and molecular mass 8000-12000 were obtained. The usage of synthesize compounds in the compositic of petroleum oils in concentration of 1% gives the possibility to increase their viscosity index for 8-12 times. The above-mentioned copolymers in the composition of oils had high stability to thermal influences (copolymers have aromatic kernel), but copolymers of o-allylphenol with alkylmethacrylates have additionaly antioxidative properties and it shows the presence of allylphenylic fragments in the composition of copolymers. The investigations in the given direction are continued.