In general, the westward typhoons are associated with zonal flow patterns. But if there was a high level cold vortex in the southern region of the subtropical high, the typhoon would pass through the subtropical high towards the North. In the paper, this kind of knotty typhoons track was discussed. The temperature, wind, divergence and vorticity fields in the subtropical high regions, and the structure of cold vortex were analysed. The cold vortex not only weakens the subtropical high, but also forces the typhoon to move northward.