FIELD: chemical industry. SUBSTANCE: described is catalyst composition comprising polymerizable groups and polymerization catalysts, e.g. Ziegler-Natt catalysts. Said composition is used for preparing polyolefins. Catalyst compositions are used to prepare polymers having wide range of molecular weight distribution and distribution of comonomeric units. Catalyst composition comprises, as metallocene complex, compound of general formula I: (1) M[XRn]xYp wherein M is IV A group metal; X is substituted or unsubstituted cyclopentadienyl group; R is polymerizable olefin group containing 3-20 carbon atoms; Y is monovalent anion active ligand, and n is integer of 1 to 10, x is 1 or 2 and when x is 1, Q is 0-3, when x is 2, p is 0-2. EFFECT: improved properties of the catalyst composition. 9 cl, 3 tbl
