The object of the present invention is to find a pharmaceutical composition and a method for treating cancer that show an excellent antitumor effect. Combinational use of 4-(3-chloro-4-(cyclopropylaminocarbonyl)aminophenoxy)-7-methoxy-6-quinolinecarboxamide and analogues thereof can result in an excellent antitumor effect when combined with a substance having a c-kit kinase-inhibiting activity.