Abstract: The paper aims to study green prevention and control of potato Phytophthora infestans. In 2012-2015, the P. infestans resistant varieties of potato authorized by Sichuan Province were tested in 10 counties including Zhaojue, Butuo, Yanyuan and so on. The results revealed that morbidity and disease index of the resistant varieties were significantly lower than those of‘Mira’, but the yield was significantly higher than that of‘Mira’, the resistant varieties could increase production and income and reduce about 25% of the drug usage in controlling P. infestans. In 2014, we introduced CARAH from Belgium and set up test point for the prediction of the disease in Xuyong, used Hobo to gather meteorological data in time. The results revealed that the first disease time was May 30 by the field investigation, and May 31 predicted by CARAH model, the results were generally consistent. We expanded the prediction to 7 counties in 2015, the results revealed that CARAH model was applicable to P. infestans prediction.