Abstract: The invention provides N-aryloxyacyl-N-phenyltetrahydrophthalamic acid derivatives represented by the general formula [I], a method of producing the same, and a herbicide containing the same as the effective components, ##STR1## wherein X and Y each individually represent hydrogen atoms or halogen atoms, Ar represents a substituted or unsubstituted phenyl group or naphthyl group, R.sup.1 represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a lower alkenyloxy group, a lower alkynyloxy group, a lower alkoxyalkoxy group or a lower alkoxycarbonylalkoxy group, R.sup.2 represents a hydrogen atom or a lower alkyl group, R.sup.3 represents a hydroxyl, a lower alkoxy group, a lower alkenyloxy group, a lower alkynyloxy group, a lower alkoxyalkoxy group, a benzyloxy group or a lower alkoxycarbonylalkoxy group, and m is an integer ranging from 0 to 5. This herbicide which is very useful can be widely applied to upland, paddy field, orchard, turf, forest, non-crop land, etc.