Abstract: In this paper,the kinetic characteristics and heat moisture and momenturn budgets of troposphere averaged over South China are discussed.The calculation result indicates that the characteristics during active monsoon period are different either from that during cold air outbreaks or from that during the active monsoon period over South China Sea.There exists downward motion in the sw monsoon layer and upward motion above.The heat budget indicates that there is apparent heat sink and apparent moisture source in the monsoon layer and apparent heat source in the easterly layer. The sources and sinks are mainly caused by vertical motion. The momentum budget indicates that the momentum profit and loss come largely from ageostrophic wind.Further,the contribution of the sub-grid eddies to the balance of moisture and heat is primarily discussed.The vertical transport is very active during sw monsoon period.It plays a greater role than it does in the process of air-mass transformation.