Abstract: Taking Phaseolus vulgaris Linn.as test material, the bacterial OTUs, diversity index and species identification on leaf surfaces of Phaseolus vulgaris Linn.were investigated in greenhouse under different nitrogen and potassium application using high-throughput sequencing method based on 16 S rRNA hypervariable region V3-V4,in order to provide a reference for the study on precision fertilization and plant-microorganism relationship.The results showed that the bacterial OTUs number on Phaseolus vulgaris Linn.phyllosphere significantly decreased under high and deficiency nitrogen, high potassium, while the OTUs number increased under potassium deficiency.Alpha diversity analysis showed that the richness and diversity of bacterial community obviously increased under normal nitrogen and potassium deficiency, and significantly decreased under excessive nitrogen and potassium fertilization, or nitrogen deficiency.The phyllosphere bacterial community showed the dominant phyla were Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria.Excessive and lack of nitrogen and potassium could lead to the overgrowth of Escherichia coli and Bacteroides,and interfere or inhibit the growth Burkholderia and Bacillus,which could affect the ability of nitrogen fixation and disease resistance of plants, and then slowing down the growth and yield of crops.