A series of the 2-benzylamino-1, 3, 5-triazine derivatives were synthesized and their herbicidal activity was evaluated. First investigation of substituents on the triazine ring revealed that the 4-methyl-6 trifluoromethyl derivatives exhibited a highly herbicidal activity. Second investigation of substituent on the benzene ring in 2-benzylamino-4-methyl-6-trifluoromethyl-1, 3, 5-triazine revealed that the 3- or 4 halogeno derivatives on benzene ring exhibited a higher herbicidal activity. Also the PET (photosynthetic electron transport) inhibitory activity of 2-(3-chlorobenzylamino)-4-methyl-6-trifluoromethyl-l, 3, 5 triazine and 2-(4-chlorobenzylamino)-4-methyl-6-trifluoromethyl-1, 3, 5-triazine indicating a strong herbicidal activity in pot tests was higher than that of simazine and atrazine.