The quasigeostrophic Q-vector method was applied to diagnose the southward movement of Kunming Quasistationary Front(KQF) in association with a cold wave in Yunnan province in February 1995.The results show that the convergence of geostrophic wind in east Yunnan at 850hPa is an important factor responsible for the frontogenesis of KQF.When the value of geostrophic frontogenesis function increases greatly at 700hPa,KQF will move southward.Furthermore,it is found that frontal rain area is correlated well to the position of the Q-convergence at the lower level.