Abstract: 【Objective】Psidium guajava cv. Jindouxiangis a new variety of guava bred by Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences and other organizations. In order to provide a theoretical basis for improving the yield and quality of guava, the effects of foliar spraying with alginate phosphorus fertilizer on fruit quality and yield of guava were studied.【Method】With the guava variety Jindouxiang as the experimental material, the leaf was sprayed different concentrations of alginate phosphorus fertilizer, and water spraying was used as control. After spraying, the yield was measured and the fruit quality, transverse diameter, longitudinal diameter, soluble solid, titrable acid, Vc,total sugar and sucrose contents were determined.【Result】Alginate phosphorus fertilizer could obviously promote the growth of guava fruit and improve the yield and quality. At the concentration of 1 500 times of liquid fertilizer, the weight, transverse diameter and longitudinal diameter of single fruit were 126.35 g, 5.49 cm and 5.83 cm, respectively, which were 39.81%, 14.85% and 14.99% higher than those of the control. Compared with the control, the yield increased by 35.75%. Meanwhile, the fruit quality was improved. The content of Vc, soluble solids, total sugar and sucrose were increased by 20.1%, 39.4%, 64.3% and 72.7%, respectively, while the titratable acid content decreased by 14.2%.【Conclusion】Foliar spraying with alginate phosphorus fertilizer could increase the single fruit weight, transverse diameter and longitudinal diameter, and increase the content of Vc, soluble solids and sugar, while the the titratable acid content were decreased. The best concentration of this fertilizer used was 1 500 times solution.