By making use of a barotropic primitive equation model, a numerical experiment on the effects of the anticyclone and cut-off low vortex in the westerlies upon the anomalous tracks of northward moving typhoon is performed. The result shows that the synoptic patterns mentioned above are responsible for the bending (to the west) and accelerating of the motion of typhoon in the later stage, and that their effects vary in intensities. The anticyclone will play a predominant role when anticyclone and the cut-off low vortex coexist.