Based on typhoon best track data from China Meteorological Administration—Shanghai Typhoon Institute and NCEP FNL 1°×1° grid data, causes for rapid dissipation of severe typhoon Fitow after its landfall are investigated by analyzing atmospheric environmental conditions, kinetic energy budgets and its structure change. The results suggest that the rapid decay of Fitow is associated with its interaction with a mid latitude trough and another typhoon Danas (1324). Before Fitow makes landfall, it obtains water vapor transported from a lower layer easterly jet connecting typhoon Fitow and Danas to its east over ocean. Meanwhile, it gets kinetic energy from baroclinic potential energy transferring due to a mid latitude trough approaching. Besides, a small vertical wind shear is also favorable for the development of Fitow. However, the moisture channel is broken after Fiow makes landfall and Danas moves northward. And the cold air invades into the center of typhoon, which causes the kinetic energy to convert into baroclinic potential energy. Meanwhile, the increase of vertical wind shear is also unfavorable for typhoon sustention. Fitow dissipates rapidly after its structure features lost.