The present invention provides a composition for preventing or treating cancer, comprising (S)-N-(4-(3-(1H-1,2,4-triazole-1-yl)-4-(3,4,5-trimethoxybenzoyl)phenyl)thiazole-2-yl)-2-amino-3-methylbutanamide or pharmaceutically acceptable salts thereof and taxane compound or pharmaceutically acceptable salts thereof. The composition of the present invention shows an excellent effect of cancer treatment.