Using the Universal Thermal Climate Index (UTCI),we analysed climatic characteristics of human-perceived temperature in Beijing from 1960 to 2014. Dominant climatic factors driving variation in UTCI were quantitatively analysed using sensitivity analysis methods. We found that the average annual UTCI was 9.2℃ in Beijing over the last 55 years and that people felt comfortable on the whole. Regarding decadal change, the UTCI in Beijing underwent a decrease (1960- 1970),increase (1971- 1990) and high stable period (1991-2014). Regarding seasonal change,people feel comfortable in spring and autumn. Moderate heat stress and moderate cold stress were detected in summer and winter, respectively. A significant increase in the UTCI was detected beginning in the mid- to late 1980s; warming in spring and winter is more obvious than summer and autumn. The decrease in strong cold stress days was obvious in Beijing (-5.8d/decade) and variation in moderate cold stress days has increased over time (2.6d/decade). Linear trends in moderate heat stress and comfortable days were 1.0d/decade and 1.6d/decade, respectively. UTCI sensitivity to temperature seems to be strong in Beijing at annual and seasonal scales. However, major factors and contributions of climate factors showed considerable differences across different seasons. For example, changes in UTCI were related to increasing temperature and decreasing wind speed in winter, whereas increasing temperature and relative humidity were major driving forces in summer. These results and sensitivity analysis were validated under given conditions based on modification of the real data set.