Based on the situation of water resources utilization over the Sanya River basin, taking 2010 as the current standard year, taking 2020 and 2030 as the planning year, the schemes of supply-demand planning of water resources were compared. Different scenarios of the schemes of water demand and water supply are made up and combined with each other. Among the final schemes of water resources allocation, water-demand scheme include water-saving measures and feedback of water supply and demand balance and water-supply scheme is to store more water resources in addition to the existing water projects, which are mainly small-scale type I reservoirs. The results show that the final scheme above could solve the problem of water shortage over each administrative partition with 90% of the frequency and balance water supply and water demand in general.