Abstract: Using 2.5×2.5 winds and presure,the angular momentum budgets are studied in this paper for TC 9012(yancy)which was kept active 65 hours after landfall.It is found that the inland TC 9012 moved into the center of a relatively stable saddle,in which large amount of humid air was entrained into the storm from the southerly jet at low-level to build up the energy of latent heat,the weak cold air coming from the north provided it with baroclinic energy,while the vorticity transfer of geostrophic angular momentum on the radius 4°-8°from the cyclone center at upper troposphere and the input of cyclonic angular momentum produced by the β term are immediate factors maintaining the central pressure and maximum winds.