Abstract: Using the data of a cold front event which affected Changjiang–Huaihe area on 27—28 April 1983, the relationship between the acceleration of upper jet stream and middle lower frontogenetical function is discussed. The results explain that in the earlier period of this case, the acceleration is an important contribution to the middle layer frontogenesis but in the latter period baroclinic wave with energy from the basic flow would lead to the lower layer frontogenesis.