Abstract: Based on the data of the west Pacific subtropical high area index and equatorial eastern Pacific SST during 1951—1984, the long-term evolutive characteristics of the subtropical high and their relations with the SST and solar activity have been investigated. It is found that the intensity of the subtropical high has the obvious staginess and periodicities with 3. 2, 3. 3, 11. 3 and 22.5 years. There are different period lengths during different stages. The 3—4 year oscillation of the subtropical high is controlled by SST. When the intensity of the subtropical high evolutes from weak to strong, the change of the SST will be ahead of the former one, and vice versa. The periods of 11.3 and 22.5 years would be influenced by solar activity. All of the turning years of the subtropical high’s stage are almost around sunspot maxima and minima with 11 year period. The subtropical high would be strong in odd cycle of solar activity and weak in even cycle of solar activity. These results would be useful for the long range forecasting of the subtropical high.