The study on the change law and regional differences of the vegetation phenology in the mountain transitional zone under the influence of global warming is of great significance to reveal how the transition zone responds to climate change. Based on the remote sensing data of the MODIS EVI₂, our research focused on remote sensing retrieval of vegetation phenological parameters and created the dataset of the vegetation phenology by remote sensing monitoring in the Qinling Mountains from 2000 to 2017. We further analyzed the changing characteristics of the spatiotemporal pattern and its north-south differences of the vegetation phenology in the past 18 years. The following results were obtained in this study. (1) The change in vegetation phenology in the Qinling Mountains showed obvious topographic and climatic regional differentiation rules, especially in the high-altitude area. The growing season start (GSS) of the whole region mainly occurred on the 70th-130th day of year (DOY), 83.29% of the regions showed an advance trend, mainly concentrated in advance at 0-5d/10a (44.46%) and 5-10d/10a (28.60%). The growing season end (GSE) mainly occurred on the 270th-310th DOY, and the changing trend was not obvious, 50.17% of the regions were delayed. The growing season length (GSL) was concentrated within 150-210days, 65.34% of the regions showed an extended trend, the extension is scattered in 0-5d/10a (19.28%), 5-10d/10a (20.71%) and 10-15d/10a (14.12%). (2) The GSS response to climate change was significantly greater than that of the GSE, and there were not only regional differences but also seasonal differences in the Northern-Southern slopes in the Qinling Mountains. The GSS in the northern slope was approximately 6.2 days earlier than the southern slope on average and the southern slope had a more significant advance trend. The GSE in the southern slope was approximately 5.8 days later than the northern slope on average and the delay trend of GSE in the northern slope was more significant. The GSL extended with an average rate of 3.7 d/10a, and the extension trend was more significant in the northern slope. The GSL were approximately 114.6-249.7 days in the northern slope and 91.4-231.0 days in the southern slope. (3) The GSS, GSE, and GSL showed significant altitude sensitivity, and the changes of them with the rising altitude showed obvious differences between the northern and southern slopes. As the altitude increase, GSS was gradually delayed, GSE was gradually advanced, and GSL was gradually shortened. At the altitudes of ≤ 600m and ≥ 2700m, the fluctuation range of the three with the altitude was relatively large. With an increase in altitude of 100 m in the northern slope, there was a delay in the GSS by 1.76 days, an advancement of the GSE by 0.25days, and a shortening of the GSL by 2.01 days. For the southern slope, the GSS was delayed by 1.50 days, the GSE was advanced by 0.44 days, and the GSL was shortened by 1.94 days. (4) The changes of GSS, GSE, and GSL in the vertical vegetation zone, especially in the ≤ 600m vegetation zone and the alpine shrub meadow zone, had the most obvious differences between the northern and southern slopes. The three parameters in the northern slope and the southern slope were converted in the alpine shrub meadow belt. The GSS, GSE and GSL in the northern slopes were in sequence of 3.5days earlier, 2.9 days later and 6.4 days longer later than in the southern slope respectively.