Abstract: In this paper, five-year simulated data from a low-resolution global spectral model are analyzed in order to study dynamical features and propagation characteristics of intraseasonal oscillations over the mid-high latitudes and the tropical atmosphere. The simulation shows that there is the 30-50 day periodic oscillation in the low-resolution spectral model and it is found that propagation characters of intraseasonal oscillations over the mid-high latitudes and the tropics are different. In the velocity potential field, the 30-50 day oscillations in the tropical atmosphere act as migrating latitudinal waves with wavenumber at 1, while following the pattern of east-west dipole from equatorial western Pacific to the Indian Ocean in the divergent wind field. On the other hand, the 30-50 day oscillations in mid-high latitudes appear as the variations in phase and amplitude of the standing planetary waves, which are related with the transformation of teleconnecting pattern for the area. The energy is transferred not only between the tropics and the mid- high latitudes, but also between different regions over the tropics. Through the energy transfer, the relationship has been built between the 30-50 day periodic oscillation over the mid-high latitudes and over the tropics.