Abstract Novel diphenyl ether compounds of the general formula: <IMAGE> (I) wherein X represents a hydrogen atom or a nitro group, process for preparing the same and diphenyl ethers of the general formula: <IMAGE> (II) wherein R represents a hydrogen atom, or substituted or unsubstituted alkyl group, alkenyl group or alkynyl group, and Y represents an oxygen atom, a sulfur atom, or the group <IMAGE> wherein R' is defined as R above by reacting 2-chloro-4-trifluoromethylphenyl-3,4-dinitrophenyl ether with a compound of the general formula: RYH (III) wherein R and Y have the same meanings as defined above, respectively. The latter diphenyl ether compounds of the general formula (II) are useful as herbicides.