Abstract:In this paper,the external forcing factors and internal variabilities which impact the Western North Pacific tropical cyclone activity (WNPTC) on the sub-seasonal to seasonal time scale were reviewed,along with the associated mechanisms.Additionally,the developing history and current situation were summarized for the prediction techniques,including statistical,dynamical and hybrid statistical-dynamical approaches.Also discussed were several scientific issues which require further research,as well as the future trends of prediction technique development.