Abstract: Using the latest-generation GPM (Global Precipitation Measurement) IMERG (Integrated Multi-satellitE Retrievals for GPM) satellitebased precipitation data as well as sea surface temperature (SST) , air-sea (land surface-atmosphere) heat flux and wind date supplied by NCEP, the intensity changes and precipitation structure characteristics during super typhoon Lekima (2019) were analyzed. As results firstly From 14:00 BST 4 to 02:00 BST 9 August 2019, Lekima intensified obviously due to significantly weakened environmental vertical wind shear (VWS), sensible heat and abundant latent heat which gained from the warm ocean in conditions of SST 29.6-30.4℃, sufficient vapor and energy provided by extremely strong southerly low-level jet in the east of Lekima. From 08:00 BST 9 to 08:00 BST 13 August 2019, when Lekima was approaching the land and landed, it weakened obviously due to significantly intensified environmental VWS, significantly decreased latent heat, loss of sensible heat, significantly weakened southerly lowlevel jet in the east of Lekima, the intrusion of cold dry air in the middle and low troposphere in its circulation and the land surface friction after its landfall. secondly, when the environmental VWS ≥ 5 m/s, whether Lekima moved slowly (motion speed ＜5 m/s ) or fast (motion speed ≥ 5 m/s), the environmental VWS was a dominant factor for the rainfall asymmetry in both the inner (defined as the inner 100 km) and outer rainband region (r = 100-300 km) of Lekima. The Lekima's heavy rainfall occurred downshear to downshear-left of the environmental VWS vector in both the inner and outer rainband region. When the environmental VWS ＜5 m/s, whether Lekima moved slowly or fast, the rainfall asymmetry in the inner rainband region depended on both the environmental VWS and the Lekimas motion, while in the outer rainband region, the environmental VWS was still a dominant factor for the rainfall asymmetry. That is to say, in the inner rainband region, heavy rainfall occurred along with downshear to downshearleft of the environmental VWS or ahead of Lekima, while in the outer rainband region, heavy rainfall was dominated by VWS and distributed in the direction along the downshear of the environmental VWS vector. In general, the influence of environmental VWS on rainfall asymmetry in both the inner and outer rainband regions of Lekima was much stronger than that of the Lekimas motion.