The invention provides an herbicide composition, which contains as active ingredients a Component A selected from the group consisting of an oxopyrazine derivative represented by the following Formula X and salts thereof, and a Components B described in the Specification, and which is capable of controlling effectively the growth of an plant undesirable for a useful plant, is highly safe to a useful plant, and exerts high effect at a low dosage:where R represents a lower alkyl group having 1 to 6 carbon atoms, and X represents a halogen atom, respectively.
