Abstract: On the basis of GMS images, radar echo pictures, conventional data and 116 hourly rain gauge records, the temporal and spatial scales and areas of heavy rain are analysed for 17 landing tropocal cyclones. The meso-and-fine scale characteristics of the heavy rain and its mesoscale osillations in intensity variation are revealed, and two interactions among the circulation systems of different scales inside the cyclones are presented. Finally, the case of typhoon Peggy in 1986 is studied in detail.