Abstract: The present invention provides a polishing composition which can remove a natural oxidized layer on a silicon wafer and can efficiently polish the silicon wafer. The polishing composition of the present invention comprises colloidal ceria and an alkaline polishing composition. The polishing composition of the present invention may further comprise a chelating agent. The present invention includes a polishing method comprising removing an oxidized layer with colloidal ceria; a polishing method comprising removing an oxidized layer with colloidal ceria and polishing a silicon wafer with an alkaline polishing composition; and a polishing method comprising polishing a silicon wafer with a polishing composition comprising colloidal ceria and an alkaline polishing composition. Further, the present invention relates to a polishing composition kit comprising colloidal ceria and an alkaline polishing composition.