Observational analysis is conducted of the effects of winter Pacific SSTA on the storm track and jet stream.It is shown that the positive Kuroshio (equatorial central and eastern Pacific) SSTA in winter can give rise to northward (east-and south-ward) movement of both the storm track and jet stream, and lead to substantial enhancement in the entrance aera of the storm track (central and eastern Pacific), but leave the center of jet stream little variation in intensity.As such, the jet stream varies in position and intensity mainly as a result of the change of temperature gradient in the tropics and subtropics,while the variation of the storm track in position and intensity is not only related to the jet stream,but also to the intensified baroclinicity which is mainly caused by diabatic heating.