Abstract: An efficacy trial of three pesticides on rice planthopper was carried out in field in order to select the suitable pesticide and determine the optimal dosage for rice planthopper in Ninghua County. The results showed that 25% buprofezin WP, 20% trichlorfon·fenobucarb EC, and 25% buprofezin·profenofos WP had efficient controlling function to planthopper, and the control efficiency of 25% buprofezin WP was the best, the follows were 25% buprofezin·profenofos WP and 20% trichlorfon·fenobucarb EC. The recommended doses for application in field production were 25% buprofezin WP 20g, 25% buprofezin·profenofos WP 75g, and 20% trichlorfon·fenobucarb EC 225 mL per 667 m² respectively.