In this project, Pengxi county, one of the impoverished areas in Sichuan province, is selected to be the target area, where the rural population is living in a poor nutritional composition with non-carotenoid sweetpotato being the major staple food and thus vitamin A deficiency prevails in a large number of local people. It has been proven that biofortification is one of the most economical and effective strategies to tackle the problem of malnutrition amongst poor people. To this end, the conventional breeding technologies will be employed to select new sweet potatoes with elevated carotenoid contents and extend them in the target area, Pengxi county, and the nutritional effects of such varieties on local people will be evaluated in detail by the experts in nutrition and disease prevention. This project will be focusing on ： breeding and extension of carotenoid-rich sweetpotato varieties, and evaluation on nutritional status of target population. The final goal is to extend carotenoid-rich sweetpotato varieties for 8800 hectares in total in Pengxi county and thus attenuate or eliminate vitamin A deficiency amongst 70,000 local people.