The results of 8 kinds of different fungicides on Potato Late Blight in field efficacy trials showed that 50%the control effect was 87.65%. The yield increasing rate was very remarkable with Sideyi of 50% WP and 60% WP duplex fullmark and the loss was restored 55.54% and 47.44%. Sideyi WP, 60% Fuma WP duplex, 25% Rick SC, 80% M-45WP, 30% Fumin SC No. 5 kinds of Fungicides on Potato Late Blight control effect are more than 70%, the effect of prevention and cure with 50% Sideyi WP was best,