Abstract: A diagnostic study is made of a cold wave-related anticyclone in East Asia, for 26—30 January 1980, by using the potential vorticity equations. The results show that at the initiation stage in the vicinity of anticyclonic center there is a low potential vorticity area where it decreases (increases) with the intensification (descension) of the high; when the high developing it descends from the middle troposphere to the nearer ground layer, when the high decaying it ascends from the lower troposphere; while the potential vorticity in upper troposphere increases with the intensification of surface high. The various terms in the potential vorticity equations have made very different contributions to the evolution of the anticyclone. The first contribution comes from the geostrophic advection of potential vorticity and the divergence term of geostrophic deviation wind. The secondary are the advection of geostrophic deviation wind and radiation heating (cooling). The twisting term and thermal wind term could be ignored.