A COMPOSITION COMPRISING A CARBOXAMIDE COMPOUND REPRESENTED BY FOLLOWING FORMULA (I), WHEREIN R1 REPRESENTS A HYDROGEN ATOM OR A METHYL GROUP, AND R2 REPRESENTS A METHYL GROUP, A DIFLUOROMETHYL GROUP OR A TRIFLUOROMETHYL GROUP, AND ONE OR MORE ACYLALANINE COMPOUNDS SELECTED FROM GROUP (A) CONSISTING OF METHYL N-(METHOXYACETYL)-N-(2,6-XYLYL)ALANINATE AND METHYL N-(PHENYLACETYL)-N-(2,6-XYLYL)ALANINATE IS PROVIDED BY THIS INVENTION, AND THIS COMPOSITION HAS AN EXCELLENT EFFECT FOR CONTROLLING PLANT DISEASE.