There is disclosed a 1-phenyl-4 trifluoromethyl-uracil derivative of the general formula: (* CHEMICAL STRUCTURE *) wherein R1 is hydrogen or methyl, and R2 is C1-C7 alkyl or C3-C7 cycloalkyl optionally substituted with C1-C3 alkyl. Also disclosed are a herbicidal composition containing this derivative as an active ingredient and a method for exterminating undesired weeds by application of this herbicidal composition.
