An analysis is made of the temporalspatial distribution, seasonal variation and tendency of various tropopauses by means of statistical methods, and the distribution features of the tropopauses and the variation regularities of height and temperature are revealed, based on the upperair sounding data of seven stations from 1970 to 2001 over Qinghai Province. The results indicate that various tropopauses have different occurrence frequencies at different stations; the polar and tropic type tropopauses differ not only in heights, but also in seasonal variation; the highest tropopause corresponds to low temperature and the lowest corresponds to high temperature. The annual mean height (temperature) of tropic type tropopauses shows an increasing (decreasing) tendency. These are related with the decreasing of stratospheric ozone and temperature, as well as the rising of the troposphere in recent years.