Yindaruqin is a large scale water supply project diverting water from the Datong River to Qinwangchuan irrigation area in Yongdeng County in the middle part of Gansu Province.The project has played an important role in improving local farming conditions and poverty situation,settling farmers from poor mountainous areas and promoting local economic and social development.However there are still some problems in achieving the designed project outputs due to influence of the various factors,which are mainly known as water supply volume haven't reach expected standards and water allocation haven't been fully optimized.Based on adequate primary information and data as well as current water demand and supply situation and water use trend in water supply areas,Yindaruqin irrigation area and it's possible surrounding irrigation areas were taken as an unified research area and considered as Yindaruqin water supply area to set up an optimized water allocation model with optimal economic,social and environmental benefits and restricted within water supply and demand volume by applying systematical water resources analysis theory.In order to serve for the various water users in different area and make the extra water resources available for use,an optimized water allocation scheme has been determined in both short-and long-term with the model,which is very important to get most project benefits and promote sustainable local economic and social development.