〔Abstract〕 Objective To compare the differences in fungal community composition between lesional and non- lesional scalp areas in patients suffering from severe alopecia areata（AA），and compare these with healthy scalp areas in control subjects. Additionally，to preliminarily explore the changes in scalp fungal communities in severe AA patients and their potential underlying immunological mechanisms. Methods A total of 20 severe AA patients and 18 healthy controls were enrolled. Skin swab samples were collected from lesional and non-lesional scalp areas of severe AA patients，as well as from the normal scalp of healthy controls. The fungal internal transcribed spacer （ITS）region was amplified and analyzed using high-throughput sequencing. Results The lesional scalp areas of severe AA patients exhibited higher α-diversity and species richness in fungal communities. Notably，the relative abundance of Ascomycota，along with genera such as Mycosphaerella，Aspergillus，Penicillium，and Wallemia，sig⁃ nificantly increased in the bald regions. In contrast，Acremonium and Schizophyllum were more predominant in the non-lesional areas of severe AA patients. Conclusion Distinct region-specific differences in scalp fungal micro ⁃ biota in severe AA patients suggests that fungal dysbiosis may play a potential role in the pathogenesis of alopecia areata. These findings provide new insights into the disease characteristics of severe AA from the perspective of scalp microecology.