Air temperature lapse rate (gamma) is taken as one of key input parameters when we evaluate the response of the mountain ecosystem to climate change, and its accuracy is very useful to the related research in the future. In this paper, based on the datasets built based on data from standard meteorological stations in Mt. Taibai, the tempo- spatial distribution characteristics for the variations of gamma were evaluated by using DEM images at a 25-m resolution as well as daily average temperature during the period of 2013- 2015. The average value of annual gamma on the northern slope (0.513℃/100 m) was larger than that on the southern slope (0.499℃/100 m) during the three years, and a greater variation in different altitude regions was found on the northern slope than on the southern slope. The variability of gamma was significant at different time-scales. At the seasonal scale, the peak of gamma (0.619℃/100 m) on the northern slope occurred in summer, while the peak of gamma (0.546℃/100 m) on the southern slope appeared in spring. Meanwhile, the minimums of gamma on both slopes (0.390℃/100 m on the northern slope and 0.449℃/100 m on the southern slope) were found in winter. Compared with the southern slope, the values of gamma on the northern slope were higher in spring and summer, while they were lower in winter and almost the same in autumn. At the monthly scale, the larger values of gamma appeared in the warmer months on both slopes, and the larger variation in gamma was found on the northern slope. The values of gamma were higher on the southern slope than those on the northern slope in January, February, November and December, while they were lower from May to September. The results clarified the rule of temperature- altitude variations in Mt. Taibai in recent 50 years, which could provide a theoretical basis for the quantitative researches on temperature distribution characteristics and the response of the ecosystem to climate change in the mountain areas.