Based on the observation of 97 weather stations in Hunan province in the past 50 years, selected three main factors of climate temperature, humidity and wind speed to set up evaluation model, and studied the change of climate adaptability in Hunan. The results show that: at an altitude of 1 000 m below, human comfort index is negative three to three. 60.1% months are comfortable or relatively comfortable with climate probability space distribution characteristics of mainly seen in the southwest and southeast and less seen in southern or eastern of Hunan, the rest months are less comfortable or uncomfortable, most of which are cold rather than warm; In Hunan province the comfortable climate is in May and September, and the cool or comparatively comfortable climate is in April and October, warm and relatively comfortable climate is in June, and cold weather lasting from December to February is less comfortable or uncomfortable; In March the climate evolves from uncomfortable to respectively comfortable, and the opposite change appears in November; In July and August the climate is warm and uncomfortable. Districts or months of uncomfortable cold climate are significantly reduced, while numbers of districts or months in uncomfortable warm climate are in the raising trend. In the altitude of 1 000 m above area, human comfortable index appears from negative four to zero.