Abstract: The changes of the boundary between subtropical and warm temperate zones and the spatiotemporal evolution of the actively accumulated temperature of ≥10 ℃ (AAT10) in the Qinling Mountains from 1960 to 2019 was analyzed by using the sliding mean temperature over five days, the Mann-Kendall test, and the Anusplin method based on the daily average temperature data from 74 meteorological stations in and around the Qinling Mountains (QMs). The results show that (1) at the temporal scale, the AAT10 had increased at a rate of 71.72 ℃·(10 a)^-1 in the QMs since 1960. The areas of 1 000 < AAT10≤2 000 ℃ and 2 000 < AAT10≤3 000 ℃ decreased from 1960 to 2019, and the areas of AAT10>4 000 ℃ and 3 000 < AAT10≤4 000 ℃ increased from 1960 to 2019. The area of ≤1 000 ℃ increased from 1960 to 1989 and decreased from 1990 to 2019. (2) At the spatial scale, the AAT10≥10 ℃ in the Qinling Mountains showed a trend of "lower in the middle and higher in the periphery", "more in the east and less in the west", and "more in the south and less in the north"; additionally, it occupied the largest area and was followed by that of AAT10>4 000 ℃ and 2 000 < AAT10≤3 000 ℃, and it gradually decreased from low altitude to high altitude. The area of the high accumulated temperature increases and the area of the low accumulated temperature decreases. The AAT10 in the QMs increased significantly, among which the north slope of the QMs increased significantly. (3) In contrast to period Ⅰ (1960-1989) and period Ⅱ (1990-2019), the subtropical-warm temperate boundary climbed significantly to higher altitudes and moved northward, and in period Ⅱ, the "leapfrog" in northern Qinling entered the subtropical climate pattern. As the climate warms, the boundary of the subtropical zone may break through the Qinling Mountains.