Based on CIMSS/MIMIC data, Taizhou radar data and typhoon location and intensity determination data of the National Meteorological Center, this paper analyzes the structural characteristics of the concentric eyewalls of Typhoon “Lekima” (1909) for 33.5 hours. The results are as follows:(1) The convection has exchanged twice between inner and outer eyewalls due to the topography when “Lekima” passed near Miyako Island or the adjustment of its spiral structure. (2) When the intensity of typhoon is strong and stable, the deviation of typhoon's inner eyewall circulation will not cause the change of typhoon's intensity. On the contrary, the stability of typhoon's intensity makes the inner eyewall circulation be reorganized and developed again, and the structure of the concentric eyewalls develops steadily. (3) Radar echoes show the inner eye wall has a 3-hour period of formation and disappearing. The asymmetric friction effect determines that the convective exchange between the inner and outer eyewalls mainly occurs in the northwest of the moat region.