A component of a catalyst for polymerizing an olefin, comprises: a carrier containing an inorganic oxide selected from silica, alumina, zirconia and titania and having a crushing strength of 0.5 to 25 MPa; and at least one member selected from oxides or hydroxides of metals of the groups 2, 3, 4, 13 and 14 in the periodic table, the metals being different from the metal constituting the inorganic oxide in the carrier, wherein the at least one member is supported on the surface of the carrier, so as to provide a novel catalyst component suitable for particle polymerization of an olefin and enabling to easily change molecular weight distribution of the resultant polymer.