Abstract:By using the NCEP/NCAR reanalyzed data, the differences of the midupper troposphere temperature in the areas of the same latitude are compared, based on the temperature variations in the midupper troposphere over the Tibetan Plateau (500 to 200 hPa). TDI (Tibetan middlehigh level temperature zonal Deviation Index) is defined by the zonal temperature deviation. Moreover, the characteristics of multiple time scale variations of the index in spring and summer are also presented. Major conclusions are: (1) From spring to summer, the Asia midupper troposphere warm center moves westward from the west Pacific to the land and controls the whole East Asia gradually, and then retreats. The disturbance temperature warm center in spring moves westward from the southeast of China to the south of the Tibetan Plateau, and reinforces gradually, but it is stable in Southern Tibetan Plateau in summer. (2) The annual variation curve of TDI shows a single maximum obviously. The thermal effect increases gradually in April and reaches the maximum in July, then decreases rapidly after September. (3) The maximum, minimum and average value of TDI in all months are high in summer and low in winter.TDI in summer changes slightly. (4) The interannual change of TDI is obvious, but the index of spring (summer) has certain (obvious) monthly variation and there is no obvious linear trend.