The present invention relates to a method of homo- or co-
polymerization of alpha-olefin by means of using a catalyst
system which comprises the following components: (1) a
solid complex
titanium catalyst produced by means of a production method comprising the following steps: (a) preparing a
magnesium compound solution by dissolving a
magnesium halide compound and a compound of Group IIIA of the Periodical Table in a
solvent of mixture of cyclic ester, one or more types of
alcohol, a
phosphorus compound, and an organic
silane; (b) precipitating the
solid particles by reacting said
magnesium compound solution with a transitional
metal compound, a
silicon compound, a
tin compound, or the mixture thereof; and (c) reacting said precipitated
solid particles with a
titanium compound and
electron donors; (2) an organometallic compound of
metal of Group IIIA of the Periodical Table; and (3) external
electron donors comprising three or more types of organo-
silicon compounds, wherein the melt flow rates of the homopolymers obtained from
polymerization by individually using said organo-
silicon compounds under the same
polymerization conditions are 5 or less, 5~20, and 20 or higher, respectively. According to the present invention, it has an
advantage of obtaining polymers of broad molecular
weight distribution with high
hydrogen reactivity and melt flow rates while maintaining high stereoregularity and yields for olefin homo- or co-polymers during homo- or co-polymerization of alpha-olefin having three or more carbon atoms.