An N-[4-(substituted benzyloxy)phenyl]-N'-methyl-N'-methoxyurea of the formula: ##STR1## wherein X, which may be the same or different, is halogen, nitro, cyano, trifluoromethyl, lower alkyl or lower alkoxy and n is an integer of 1 to 5, which shows a pronounced herbicidal activity against a wide variety of weeds in the cultivation of soybean, kidney bean, peanut, cotton or rice plants without any material toxicity to mammals and said crop plants.