Abstract: Numerical experiments are done of abnormal motion of tropical cyclones(TC) moving across the subtropical high using the barotropic primitive equations model.It is shown that sensitive factor having direct effects on the TC motion include the storm's own characteristics,its longitudinal distance between the centers of the subtropical high and TC,and the location and changes in intensity of the latter.The work also illustrates how TC interacts non linearly with the synoptic-scale subtropical high next to it and the β effects.