Vegetation and its characteristics are largely controlled by regional landforms and climate. The Qingling-Daba Mountains are located in a transitional zone between the subtropical and the warm temperate climate in China, where a complex relationship between vegetation and climate exits. To explore this relationship, we used GIMMS_3g (1982-2015), SPOT VEGTATION (SPOT VEG) (1998-2015), and MODIS (2000-2017), the DEM, and climate data (temperature and precipitation) to quantify the spatiotemporal changes in vegetation in the Shaanxi Province of the mountains. We found that:(1) NDVI of the GIMMS_3g database increased significantly at a rate of 1.4%/10a from 1982 through 2015. For 1982-2000, NDVI of GIMMS_3g was low but highly variable (linear tendency 1.6%/10a, CV=0.4) by year, whereas a stable increasing trend appeared after 2000 (linear tendency 1.7%/10a, CV=0.2). For 2000-2015, the increasing rate was 4.1%/10a (CV=0.04) for NDVI of the SPOT VEG database. For 2000-2015, the increasing rate was 4.5%/10a (CV=0.04) for NDVI of the MODIS database. (2) High vegetation coverage was found from MODIS for 2000-2017, primarily in the mountainous regions (e.g., Qinling Mountains, Micang Mountains, and Shennongjia), whereas low cover was detected at high altitudes in the west and low altitudes in the east. For the Qinling Mountains, NDVI increased and decreased with elevation. (3) The increase and decrease of vegetation coverage during 2000-2017 accounted for 96.90% and 3.10% of the total land area, respectively. Meanwhile, the vegetation cover at low altitude appeared more protected than that in the high-altitude areas. (4) Annual mean temperature in the study area increased by 0.49℃/10a during 1982-2015, whereas the precipitation showed no significant change. For 2000-2015, we found that vegetation cover (based on SPOT VEG and climate data) was positively correlated with temperature, but not with precipitation. The correlation analysis further demonstrated that vegetation cover was more strongly correlated with temperature in the Qingling-Daba Mountains. In the Qinling Mountains, the correlation was significant between NDVI and temperature in the high-altitude areas, and between NDVI and precipitation in low-altitude areas.