There is a close relationship between surface water and groundwater in semi-arid and arid areas of China, and thus researching on the interactions of them is of importance for reasonable water resources development. This paper took Bulang River basin as case study, analysis and discussion were conducted to water chemistry and isotopes tests results of water samples. The results show that surface water in Bulang River basin mainly relies on precipitation recharge, partially on groundwater recharge, the hydrochemistry type of surface water is mainly Ca-HCO₃ with low salinity.