Olefins are homopolymerized or copolymerized in the presence of a catalyst containing a reaction product obtained from vanadium oxytrichloride and 2,2'-thiobis(6-t-butyl-4-methylphenyl), an organic aluminum compound, such as trimethylaluminum, and an ionized ionic compound, such as N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, and the like. By using this catalyst to polymerize ethylene with an .alpha.-olefin, such as propylene, 1-heptene, 1-octene, and the like, or a non-conjugated diene, such as 5-ethylidene-2-norbomene, and the like, a polymer having a high degree of copolymerization is obtained.

Олефины homopolymerized или copolymerized in the presence of катализатор содержа продукт реакции полученный от oxytrichloride ванадия и 2,2'-тюиобис(ь-т-butilovy1-4$-methylphenyl), органической алюминиевой смеси, such as триметилалюминий, и ионизированная ионная смесь, such as tetrakis(pentafluorophenyl)borate н, N-dimethylanilinium, и подобие. Путем использование этого катализатора полимеризовать этилен с alpha.-olefinom, such as пропилен, 1-heptene, 1-octene, и подобие, или non-conjugated диен, such as 5-ethylidene-2-norbomene, и подобие, получен полимер имея высокий степень copolymerization.