Based on the upper-level radiosonde observation data of seven stations from 1970 to 2001 in Qinghai Province, the abrupt change and abnormality analysis of 500 hPa temperature and height were analyzed by the statistical method, and the basic facts and regulations were found. The changes of height and temperature at 500 hPa, especially the effects of abnormal changes on surface air temperature and precipitation and their mutual relation, are discussed. The results show that there were abrupt changes from low (cold) to high (warm) at 500 hPa in height and temperature at most stations in the middle 1980s; since 1987, there have been an increasing trend in positive abnormality and a decreasing trend in negative abnormality for height and temperature, which were correlated with the surface air temperature change.