The present invention provides a gene coding for the following protein (a) or (b) showing a high level of resistance to PC herbicides or sulfonylurea herbicides: (a) a protein which consists of an amino acid sequence of any one of SEQ ID NOS: 2, 4, 6 and 8; (b) a protein which consists of an amino acid sequence derived from the amino acid sequence of any one of SEQ ID NOS: 2, 4, 6 and 8 by substitution, deletion or addition of at least one or more amino acids, has resistance to a pyrimidinyl carboxy herbicide, and has acetolactate synthase activity.