In this paper,using the data of winter daily frozen depths from 72 stations and dynamic Q-index and wavelet means,the features of temporal and spatial distributions of seasonal frozen soil in the Tibetan Plateau has been analyzed.The results show that the dynamic Q-index of seasonal frozen soil between meteorological stations in the Tibetan Plateau is very small in most Tibetan Plateau,but it is large partly in the southern plateau,which shows that the dynamic structure of seasonal frozen soil is consistent each other in the main plateau.The Q-index between fore and aft the middle 1980s is small too for each meteorological station,but it is large in a few stations in the southeastern plateau and the Qaidam Basin,which reveals that the dynamic structure of seasonal frozen soil does not abruptly change in most Tibetan Plateau.The seasonal frozen soil in Tibetan Plateau has a depth decreasing trend as a whole.The maximum average frozen depth in winter is more than 100 cm and the minimum is less than 80 cm.There was an abrupt change of the average frozen depth in winter in the Tibetan Plateau in the middle 1980s;the average frozen depth was about 93 cm before 1985 and 83 cm after 1986.The change in winter average frozen depth of seasonal frozen soil has a period of about 4 years.Maybe,there is a longer period for the seasonal frozen soil change,but it can not be displayed very clear because the data is not long enough.