Abstract: Full physical model MM5 has been used to simulate tropical cyclone “HuangFeng ” in August 2002. Adapting high resolution grids, the effect of structure chang es on intensity in the process of intensification was investigated. The simulati on catches evolution details to support further analysis.During the process of intensification, there exist two different synoptic syst ems in the two sides of TC circulation. One is deep subtropical high, which stre tches westwards and led adequate vapor into inner core; the other is cold votex located in the west of TC, which induced cold air to surrounding of TC circulati on through middle level to increase instability. These environmental conditions were favorable for TC intensification.According to vortexRossby waves (VRW) theory to explore the mechanism of TC in tensification, the results confirm that there exists VortexRossby like waves, which are initiated by convection as perturbation source in the northwest of TC circulation. VortexRossby waves, coupled with eyewall convective band and spir al rain band outside, propagate cyclonically in the process of intensification. Ultimately the propagation of waves leads to form a complete eye structure in th e minimum botton of sea level pressure. Mesoscale vortices axisymmetrization ar e found to transfer energy to parent vortex through nonlinear interaction. Meant imevortices also experience selfmaintain and development process. These facto rs impact on the offshore intensification. After landfall, vapor channel is cut off and cold air penetrates low level to strengthen stability of troposphere. These unfavorable conditions weaken the convective activity and lead to decay of TC intensity.