Major tropical cyclone disaster often arise from the landfalling tropical cyclones in the time period of landfalling. Some storms would dissipate shortly after the eyewall touches the land while others could maintain its cyclonic circulation 3-5 days after its landfall. Severe disasters arising from lasting torrential rain could occur if the landfalling storm maintains its circulation over land and interact with topography or mid-latitude systems. This paper will discuss the maintenance or reintensifying condition of landfalling tropical cyclones.