Abstract: Based on the actual circulation structure as well as weather characters over East-Asia subtropical region in summer, by using three-dimension non-linear forced/dissipated dynamic model, the activities of subtropical anticyclone over East-Asia have been studied and discussed. The potential enstrophy criteria of system stability have been derived and also been analysed. The criterion can provide useful reference for analysing and predicting subtropical anticyclone’s extending/shrinking as well as corresponding weather over East-Asia in summer.

Key words: subtropical anticyclone, potential enstrophy, stability criterion