Abstract: The herbicide activities of six N-nitro-diphenyl urea derivatives ( Ⅰ ) with concentration of 500 mg/L on Echinochloa crusgalli and Amaranthus viridis were tested. Ⅰ b and Ⅰ e were selected for herbicide activity test under concentrations of 125、250、500、750、1 000 mg/L on Echinochloa crusgalli and Amaranthus viridis. The results showed that Ⅰ b and Ⅰ e had restraining activities on Echinochloa crusgalli and Amaranthus viridis. The restraining activities were enhanced when their concentrations were increased.