The climatic characteristics of the severe tropical cyclone activities over the Northwest Pacific and general circulation features of atmosphere and their relationship from 1951 to 1995 were statistically analysed. The results show that 1950s and 1960s were two periods of anomalous severe tropical cyclone activities. 1960s and 1970s were two periods of anomalous typhoon activities. It was pointed out that typhoons were well correlated with the subtropical high,the westerly circulation and the Qinghai Xizang Plateau index.