The Qinling Mountains are one of the oldest mountain ranges in China and a global biodiversity research and conservation hotspot. However, there is a lack of systematic research and survey of butterfly diversity in this region. Based on the butterfly taxa, combined with the changes in natural climate, altitude gradient and season in the Qinling Mountains, the butterfly diversity and community structure changes in 12 counties in the middle Qinling Mountains were analyzed by transect surveys and platform data analyses. A total of 9626 butterflies were observed, belonging to 427 species across 175 genera and 5 families. The species richness on the southern slope of the Qinling Mountains was higher than on the northern slope. We also studied the variation in alpha and beta diversity of butterflies. The results show that butterfly species were abundant and the highest diversity was found at the middle altitudes (1000–2000 m). Moreover, there were obvious seasonal differences in both species and number of butterflies. The community similarity in spring, summer and autumn was low, with limited species co-existing. The butterflies in the Qinling Mountains reserve area were the most abundant, exhibiting no significant difference with those in the ecotone and the farm area. Finally, we did an assessment of butterflies as endangered and protected species. In conclusion, our long-term butterfly survey data show that human disturbance and climate and environmental changes jointly shape the butterfly diversity in the middle of the Qinling Mountains. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
