Abstract: To reveal the change law of human comfort in Shaanxi Province, China under the background of climate change, the spatial-temporal characteristics of Comfort Index of Human Body (I_CHB) are analyzed using the daily meteorological data observed by 94 stations in Shaanxi Province from 1971 to 2018. At the same time, the weight of every influencing factor is analyzed statistically. Analysis results can provide references for urban atmospheric environment assessment and tourism climate resource development. Results indicated that: (1) The annual average I_CHB in Shaanxi presents an ascendant trend in the past 48 a, which reaches an extremely significant level. The linear increasing trend of I_CHB in Shaanxi is 0.07 each year. The inter-annual changes in each region are basically consistent with the changes in Shaanxi Province, with upward trends of 0.05?a^-1, 0.09?a^-1, and 0.05?a^-1, respectively. The I_CHB in each season presents obvious increasing trend, especially in spring with a linear trend of 0.1?a^-1. The increasing trend of I_CHB slowed down since the 21st century, and the ICHB decreased after 2001 in autumn and winter. The annual variation of I_CHB in the four seasons of each region is consistent with the trend of the Shaanxi Province. The difference of I_CHB in summer is minimum, while the largest difference is observed in winter. Monthly changes of ICHB are of single peak type with the lowest in January and the highest in July. (2) The I_CHB in Shaanxi is between 26 and 52, and the grade is cold and cool. The spatial distribution of I_CHB is significantly different in each region, with the highest in southern Shaanxi (40-52), followed by Guanzhong (26-48), and the lowest in northern Shaanxi (33-43). The distribution characteristics of I_CHB in the four seasons are similar to those in the whole year with all showing increasing trends from north to south. The I_CHB in the four seasons of spring, summer, autumn, and winter in the province shows a rising- rising- declining- declining trend. (3) By R/S nalysis, it was found that the Hurst values of most factors were greater than 0.5, indicating that in the future, temperature will continue to rise, wind speed will maintain the current decreasing trend, and the I_CHB will increase. The climate comfort in four seasons is also expected to change. As I_CHB rises in spring, autumn, and winter, the living environment may become more comfortable, but the increasing grade of I_CHB in summer may lead to more hot days. (4) Past analysis indicates that temperature is positively correlated with I_CHB, while humidity and wind speed are negatively correlated with I_CHB. Temperature and speed are the main factors affecting the I_CHB, and the absolute values of their correlation coefficients are higher than 0.7. Humidity affects the I_CHB by temperature. The positive effect of temperature and the negative effect of wind speed in the three regions are significant. Humidity also has a greater negative impact on I_CHB in northern Shaanxi and Guanzhong but less impact on I_CHB in southern Shaanxi. The three factors in Guanzhong have greater influence on each other, but the factors in northern Shaanxi and southern Shaanxi have little influence on each other, which have a direct impact on I_CHB.

Key words: comfort index of human body, spatial-temporal characteristics, path analysis, Shaanxi Province