Abstract: A manufacturing method of polyolefin characterized in that at least one kind of olefins is allowed to polymerize in the presence of a catalyst system comprising(A) solid catalyst ingredient (A) obtained through the successive reaction steps, wherein, with a homogeneous solution involving(i) at least one member selected from metallic magnesium and hydroxylated organic compounds and oxygen-containing organic compounds of magnesium, and(ii) at least one kind of oxygen-containing organic compounds of titanium, are allowed to react in sequence with:(iii) at least one kind of organoaluminum compounds, then(iv) at least one kind of silicon compounds and further(V) at least one kind of halogenated aluminum compounds and(B) at least one kind of catalyst ingredients (B) selected from organometallic compounds, the metal of which belongs to Ia, IIa, IIb, IIIb or IVb group in the periodic table.