FIELD: polymerization catalysts. SUBSTANCE: solid component of catalyst for preparing basically amorphous ethylene- propylene copolymers essentially contains titanium compound applied on solid substance basically consisting of magnesium halide. The component is prepared as follows. Solution basically consisting of organoaluminum compound dissolved in aliphatic hydrocarbons is mixed with solution prepared by (i) dissolving magnesium halide in solvent mixture in presence of aluminum trihalide, (ii) treating solution thus obtained with tetravalent titanium compound of general formula Ti(OR)4-nXn wherein R is aliphatic, cycloaliphatic, and aromatic C1-C20-hydrocarbon radical, X is halogen atom, and n integer from 0 to 4, and (iii) optionally subjecting solution to additional treatment with electron-donor compound selected from group including carboxylic acid esters, alkyl- or alkylaryl ethers (simultaneously with or after previous treatment). Resulting solid catalyst component is then separated from combined solution and optionally purified. Method is distinguished by that above-mentioned solvent mixture is a mixture of hydrocarbyl halides or aromatic hydrocarbons. EFFECT: increased productivity of catalyst. 7 cl, 5 tbl, 22 ex
