Control effect experiment on potato late blight is conducted with 50% Shi benefit wettable powders （WP）, 60% duplex firma WP, 58% fubol WP. The results show that control efficacy of Shi benefit and duplex firma are often significantly better than 58% fubol, especially the Shi benefit drug 5 times, every 666.7 square meters can save up to 55.54% yield loss.