The rainfall distributive characteristics of strong tropical storm Bilis (2006) after the landfall and its possible formation mechanism are analyzed based on the NCEP/NCAR 1°×1° grid reanalysis data,the TBB data from FY-2C,and the precipitation data at 740 observational stations in China.The main results are as follows: (1)The strong precipitation centers of Bilis lay in the Northwest side of its surface center during its landfalling,and the heavy rain mainly occurred in Fujian and Zhejiang province;and after the landfall,those centers shifted to the West side and latter to the southwest side of Bilis’ surface center,and the heavy rain occurred in the Northeast of Guangdong Province,Fujian Province,Jiangxi Province,and the South of Hunan Province. (2)The stable and motionless Northwest Pacific subtropical high provided a stable large scale circulation background field for Bilis’ persistent precipitation during its westward movement over land. (3)The development and strengthening of the Southwest monsoon to the Southwest of Bilis greatly enhanced the moisture transfer to Bilis’ precipitation areas. (4)The interaction between storm vortex and meso-and small-scale vortices,which were resulted from the mergence of vortices and self-excitation,might be the possible formation mechanism for Bilis’ strong precipitation after its landfall.