Abstract: [Objective] In order to research the influence of chemical methods on the flower thinning effect and quality of Prunus salicina × armeniaca to screen the suitable chemical agent and concentration and to propose a simple method of flower thinning and control reasonable crop load.[Method] Three cultivars of Prunus salicina × armeniaca were taken as materials,different concentrations of three kinds of chemical flower thinning agents were sprayed at full-bloom stage and then the fruit setting rate and quality were determined.[Result]The results showed that when Fengweihuanghou was sprayed one time 20 mg/L NAA and 0.3°Be lime-sulfur at full-bloom stage,Konglongdan was sprayed 30 mg/L NAA and 0.4° Be lime-sulfur and Weidi was sprayed 30 mg/L NAA and 0.4°Be lime-sulfur,the fruit setting rate of these treatments was lower than that of the CK,and the fruit shape index,soluble solid content and sugar content and acid content were significantly improved.[Conclusion] Spraying one time 20 ～30 mg/L NAA and 0.3 ～0.4° Be lime-sulfur has better effects of flower thinning at one day or two days of full-bloom stage and can improve the quality of fruits.