Based on the data of phenological observation and daily meteorological records during 1964-2015, we studied the relationship between plant phenology variation and climate change in the Qinling Mountains region by using correlation and Partial Least Squares (PLS) regression analysis. The results showed that: (1) In the past 52 years, the climate of the study region presented a warming-drying trend at the start and the end of plant phenophase, and the warming trend at the start of phenophase is more significant than that at the end of phenophase, especially after the phenophase abrupt change around 1985. (2) The responses of the start and the end of phenophase to the change of climatic factors such as temperature, precipitation and sunshine varied differently. Before the period of phenophase abrupt change, the responses of phenophases were not significant to all the climatic factors except for the daily mean temperature. However, after the period of phenophase abrupt change, the response of phenophases was significant to all the climatic factors. The start of phenophase advanced by 3 d and the end of phenophase delayed by 12 d with the increase of the daily mean temperature by 1℃ . The start of phenophase advanced by 1.3 d with the decrease of the accumulated precipitation by 1 mm, and the end of phenophase delayed by 1 d with the increase of the accumulated precipitation by 1 mm. The start of phenophase advanced by 4.3 d and the end of phenophase delayed by 18.3 d with the increase of daily mean sunshine hours by 1 h, respectively. (3) There is a lag effect for the responses of the start and the end of phenophase to climate change. The time-lag was about 1-2 months for air temperature and about 1-3 months for the pre-period accumulated precipitation at the start of phenophase, respectively. No lag effect on the start of phenophase was observed for the sunshine hours. As related to the end of phenophase, the time-lag was about 1-3 months for the air temperature and about 1-2 months for the sunshine hours, respectively. No lag effect on the end of phenophase was found for the precipitation. (4) Both the start and the end of phenophase were jointly affected by the climatic factors, in which the air temperature was the predominant factor. Especially, the rise of the daily mean temperature plays a dominant role in advancing the start of phenophase and delaying the end of phenology.