Abstract: This paper calculated heat source and heat sink over the Tibetan Plateau (TP) during 1981 ~ 2010 by use of the NCEP CFSR reanalysis data and the “inverse algorithm”, and discussed the climate regimes and change of the thermal sources over the TP. The results suggest that: (1) The atmospheric heat source and heat sink have obvious seasonal variations over these areas. The most part of TP acts as a heat source in Spring and Summer, while it acts as a cold source in Winter and Autumn. From February to April, the scope of heat source expands gradually from northwest and northeast plateau and southwest slope to the center of TP, and its intensity enhances obviously. From May to July, The heat source over southeast part of TP enhances and expands to the west and north significantly. In July, the southern tip of TP along the Himalayan mountain area has become a strong heat source belt, with its strongest value appearing. Beginning in August, the heat source over TP starts to weaken. The areas become cold sources successively from the center to side slope of TP. In November and December, the whole TP area almost has become a cold source. (2) The yearly average intensity of the atmospheric heat source over the whole area of TP, the Eastern or the Western Plateau has obvious different change features. The intensity of heat source in the whole area of TP changes with periodicities of 2 ~ 3 years and 6-8 years, while in the Eastern Plateau is 6 ~ 8 years, in the Western Plateau is 2 ~ 3 years. (3) Over recent 30 years, the atmospheric heat sources in the whole area of TP and the Eastern Plateau have significantly enhanced trend, while in the Western Plateau it takes on a down trend.