Abstract: By taking into considerations of the factors such as the intensity of the westerly jet, the latitudinal width of the westerly current, the wave length, the width and latitudinal position of the wave, the distance the jet axis and the latitude with largest wave amplitude, and the thermal structure of the wave the movement and development of the tronghs and wedges in the westerlies are theoretically studied. Formulas for estimating the movement and development are respectively obtained. Application to 24 hours forecasting is tested and illustrated by synoptic examples. It shows that the tested results are good. And it is suggested that the theoretical results can also be applied to fiveday mean maps in the extended forecasting.