A pyrimidine derivative having the formula, ##STR1## {wherein R.sup.1 is a hydrogen atom or an alkyl group, R.sup.2 is a group having the formula R.sup.3 O (wherein R.sup.3 is an alkoxyalkyl group, an aralkyl group, an alkylcarbonyl group, a phenylcarbonyl group, a substituted phenylcarbonyl group or an alkoxycarbonyl group), a group having the formula ##STR2## wherein R.sup.4 and R.sup.5 may be the same or different and are a hydrogen atom or an alkyl group), a group having the formula ##STR3## (wherein n is 0 or 1), a phthalimide group or a dioxolanylmethyl group, and A and B may be the same or different and are an alkyl group, an alkoxy group, a haloalkyl group, a haloalkoxy group, an amino group, a monoalkylamino group, a dialkylamino group, a cyano group or a halogen atom}, and a herbicidal composition containing said pyrimidine derivative as an active ingredient.