The research work was carried out with two broad objectives. Firstly to screen most efficient high yielding disease resistance variety and secondly to manage the disease with less hazardous and useful fungicides for the benefits of farmers. Potato (Solanum tuberosum L.) is one of the most important food and cash crop . In Assam, it is grown in an area of 7.78 thousand ha producing 584 thousand ton with an average productivity of 75.71 q/ha (Gupta et al., 2009) which is very low as compared to national productivity level (187.7 q/ha). The various factors limiting yield of the crop include lack of HYV, inadequate supply of healthy seed tubers, highly dependence of rain fed cultivation and high incidence of disease and pest. Among the diseases late blight of potato incited by Phytophthora infestans (Mont) de Bary is the most destructive disease. In Assam the diseae ocuurs in epidemic form .Among the potato varieties, Kufri Megha, Kufri Jyoti, Kufri Pukhraj have been grown popularly in the state. But almost all cultivable varieties within the species Solanum tuberosum L are susceptible.Considering the economic importance of the disease present study was conducted.