Abstract: Because of heavy losses for water in soil with high gravel, the application of super absorbent polymer(SAP) provided an important channel for the water-saving research on agricultural irrigation. The authors researched soil water, transpiration, fruit yield and quality after applying SAP to apricot trees and quantitatively analyzed water using characteristics, and the research provided a theoretical basis for highly efficient and reasonable water conservation. Sapwood flow velocity (SFV) of a 15-year-old apricot tree was continuously monitored by Thermal Dissipation Sapwood Flow Velocity Probe at Beiliu orchard in Changping. The results show that: SAP obviously affects soil moisture and transpiration; there was significant difference with transpiration, in different treatments in two periods of drought. The T3 for 200 g SAP per tree improved the average soil moisture by about 21.53% as compared to T1 in the whole fruit period, and increased average diurnal transpiration by about 20.62%. At the same time, the average weight and Vitamin C content of every apricot fruit were apparently higher than those of T1 and T2. So, after application of SAP, the water use efficiency (WUE) was obviously improved with a result of high fruit quality, which was an effective method to improve WUE for the soil with high gravel.