Abstract: In this paper, a barotropic vorticity equation model is used to investigate the relationship between midlatitude response of tropic forcing from different longitudinal positions and Northern winter stationary waves of basic flow. The results indicate that for the tropic forcing over most area of Indian Ocean and Pacific the midlatitude response patterns are determined mainly by the structure of the basic flow and are supported by the kinetic energy conversion of basic flow to perturbation. These results could interpret the finding that the structure of the GCM's midlatitude response is insensitive to the longitudinal position of the SST anomaly forcing during El Niño episade. Moreover, the roles of zonally oriented low frequency dipole convective anomaly forcing appeared in observation and GCM simulaton on GCM midlatitude response are also discussed.