The present invention relates to 3,4,5,6-tetrahydrophthalamide derivatives and 3,4,5,6-tetrahydroisophthalimide derivatives having excellent effects as effective active ingredients of herbicides, and processes for preparing the same, and provides the compounds having a more efficient herbicidal activity, and efficient and industrial processes for the preparation thereof.More specifically, the tetrahydrophthalimide derivative obtained by reacting a halogen-substituted 5-cycloalkyloxyaniline derivative with a 3,4,5,6-tetrahydrophthalic anhydride, or the tetrahydroisophthalimide derivative of the present invention is reacted with various types of amines to prepare a tetrahydrophthalamide derivative represented by the general formula (I): ##STR1## These tetrahydrophthalamide derivatives and the tetrahydroisophthalimide derivatives exhibit excellent herbicidal activities in the soil treatment in the paddy field and field and the stem-foliar treatment. The tetrahydroisophthalimide derivatives are also useful as intermediates for the preparation of the tetrahydrophthalamide derivatives, etc.