Abstract: Based on ECMWF objective analysis data in winter years of 1983/84 and 1986/87, the relationships between the tropical convection and the extratropical circulation,as well as the low frequency perturbation kinetic energy, on intraseasonal time scale are investigated by use of diagnostic analysis methods.Through this study, it can be found that the difference of tropical convective intensities can bring about both the different intraseasonal teleconnection wave trains between the tropical and extratropical zones and the different dispersions of low frequency wave energy. Moreover, the tropical convection can be of an important junction factor for the intraseasonal teleconnection effect of tropical and extratropical circulations.