Climate change is one of the major driving forces for landscape evolution. The ecosystem in high altitude area has the most sensitive and fast response to climate change. In this study, we focused on the Bita lake watershed of northwestern Yunnan located in the Shangri-la county and in the southeast margin of Three Rivers Parallel Area over Qinghai-Tibet plateau mountains. The study area with small anthropogenic interference, is the ideal area to identify the coupling relationship between climate change and landscape change. Based on the meteorological data from 1958 to 2011, and the landscape area indices of class level in the years of 1955, 1974, 1981, 1994, 2005, 2011, the characteristics of landscape evolution over the Bita lake watershed under the background of climate change were studied using climate tendency estimation method, Mann-Kendall mutation method and Pearson correlation coefficient method. The results were as follow: (1) The values of mean annual temperature, mean annual active accumulated temperature, mean annual extreme high temperature, mean annual extreme low temperature, average annual precipitation were 5.9℃, 2146.1℃, 24.3℃, -18.6℃ and 631.7mm from 1958 to 2011, respectively. The temperature, active accumulated temperature and annual extreme low temperature increased significantly in the Shangri-La of northwestern Yunnan, while the increases of annual extreme high temperature and precipitation weren't significant. The average temperature was elevated about 1.94 ℃ from 1958 to 2011, and the increasing rate was much higher than that in Yunnan and China. Active accumulated temperature and annual extreme low temperature were shown to be significant warming mutation trend with an increase of 167.1℃ and 3.4℃ after the mutation in the years of 1988 and 1986, respectively. (2) The mechanism of landscape evolution was in a succession from meadow and scrub-grassland to forestland in the Bita lake watershed from1955 to 2011. The rising trends of temperature, active accumulated temperature and annual extreme low temperature were consistent with the increasing trend of forestland landscape area, but were contrary to the decreasing trend of meadow and scrub-grassland landscape area. (3) Significant correlation was found between temperature, active accumulated temperature, annual extreme low temperature and natural landscape area of meadow, scrub-grassland and forestland from 1955 to 2011. When temperature,active accumulated temperature and annual extreme low temperature were increased quickly, the area of meadow and scrub-grassland was decreased, whereas the area of forestland was increased. Temperature, active accumulated temperature and annual extreme low temperature were the main driving factors of landscape evolution over the Bita lake watershed of northwestern Yunnan, while the ecological effects of annual extreme high temperature and precipitation on landscape evolution were relatively lesser. Climate warming was conducive to the growth of the watershed dominant tree, which played an important role in formation of a succession from meadow and irrigation grass to forestland in Bita lake watershed.