Abstract：‘Longshu No.9’is bred through systematic and oriented selection from the progeny of a novel clone 93-10-237 as female parent and a line Datong G-13-1 as male parent. The variety is with middle-late maturity and about 118 days growth period. Its tuber is of flat round shape, with pale yellow flesh and light yellow and russet skin. The big and middle size tubers take above 95 %. The average dry matter content is 26.18 %, starch is 20.39 %, crude protein is 2.840 %, the VC content is 131.8 mg?kg-1 and reducing sugar is 0.201 %. Its yield is approximately 29.16 t?hm-2. It is suitable to be popularized and planted in areas with high latitude, cold and wet climate, and semi-arid areas.
