A strong cold wave entering Qinghai-Xizang Plateau during 8-10 January of 1983 is analys.ed by the isentropic potential vorticity (IPV) maps. In this process,the cold air from the stratosphere over the eastern , side of the Urals entered its appearance into the Qinghai-Xizang Plateau through the area of Balkhash Lake and Xinjiang. The weather system developed strongly in the Balkhash Lake area. Its dynamic characteristics -for the development is discussed. The feature and structure of the cold currents and the effects of the plateau are discovered.Therefore it shows that IPV maps are potentially reasonable for the analysis and forecasting of the large scale weather systems.