Abstract: The paper aims at tourism resource evaluation and tourism comfort index forecast in Xining. With ground weather observations from 1961 to 2015, the monthly and annual sequence data of vacation, human body comfort level, and temperature and humidity indexes of key tourist cities were calculated. The characteristics and changes were evaluated with the climate diagnosis method. The results showed that the comfort days in the summer of Xining had a significant upward trend, with an increase rate of 1.1 d/10 a, and an average days of comfort of 89. In Xining, summer’s cold, temperature and humidity, vacation, and body comfort indexes were in the appropriate-comfortable level and very appropriate-the most comfortable level. The climate condition for tourism or residence in Xining was comparable to that of Kunming, Guiyang, Lanzhou and Yinchuan. The climate related indexes suitable for tourism and leisure were good compared with those of other major tourist cities, and this advantage became more apparent in recent 10 years. The evaluation results provide a basis for the forecast of tourism comfort index and the comprehensive development of tourism climate resources of Xining.