Abstract: To investigate the composition and diversity of phyllosphere microbial communities in different resistant potato varieties after late blight infection, 47 potato germplasms were assayed. High-throughput sequencing was used to analyze the phyllosphere microorganisms of the disease-resistant varieties Dianshu 6 and Lishu 6 and the susceptible varieties Hezuo 88 and Qingshu 9. The results showed that among the 47 potato germplasms, there were no highly resistant or highly susceptible germplasms to late blight. Disease intensity positively correlates with the quantity of cultivable bacteria and fungi, and were negatively correlated with actinomycetes. The phyllosphere bacterial communities of the four tested species were divided into 15 phyla, 35 classes, 52 orders, 100 families and 180 genera. The dominant bacterial genera were Streptophyta and unclassified Bacteria. The foliar fungal community was divided into 13 phyla, 48 classes, 142 orders, 339 families and 777 genera, with 8 dominant fungal genera. Alpha and Beta diversity analysis indicated that the richness and diversity of phyllosphere bacterial and fungal communities in late-blight resistant varieties were significantly higher than those in susceptible varieties. LEfSe analysis indicated that 28 biomarkers (7 bacterial genera and 21 fungal genera) were positively correlated with resistance, while 8 biomarkers (1 bacterial genus and 7 fungal genera) were negatively correlated with resistance.