The invention relates to a herbicide composition containing (A) an amino acid-based herbicide and (B) a compound having a branched structure represented by formula (1): R.sup.1CH.sub.2O--(R.sup.2O).sub.nH (1) wherein R.sup.1 represents a C3 to C29 branched alkyl or branched alkenyl group, R.sup.2 represents a C2 to C4 alkylene group, and n is a mean number in the range of 1 to 30.