FIELD: catalytic chemistry. SUBSTANCE: prepolymer containing 40-80 g polyethylene per 1 mg-a titanium or vanadium prepared by ethylene polymerization in the presence of trialkylaluminium and product of sequence interaction of thermotreated silicon dioxide is used as catalyst. The latter has hydroxyl-groups with dibutylmagnesium or dibutylmagnesium and trialkylaluminium, fluoro- or tert.-butylchloride and compound of transient metal taken from the group involving tetraalkoxytitanium, titanium tetrachloride and vanadyl trichloride. Content in the solid product of the sequence interaction per 1 mg-a titanium or vanadium: magnesium 1-3.8 mg-a, aluminium 1.2-3.0 mg-a, chlorine 7.7-9.4 mg-a and silicon dioxide 0.5-2.5 mg-a at molar ratio of trialkylaluminium and solid product of sequence interaction at prepolymerization (as titanium or vanadium) 1.2-3. Process of (co)polymerization is carried out at 70-100 C, under total pressure 1.5 MPa, in the presence of hydrogen. EFFECT: improved method of catalyst preparing. 9 cl, 6 tbl
