Abstract: Using an airflow trajectory model based on the Lagrangian method (HYSTLIT_4.9), and the massive gas block tracking method, this study analyzed the moisture transport characteristics of typhoon landing on Hainan Island from 1987 to 2016, and compared the characteristic of summer and autumn. The result shows that the climatic moisture of landing typhoon mainly comes from the South China Sea, the Western Pacific Ocean and the Bay of Bengal. The one in summer mainly comes from the South China Sea and the Bay of Bengal-Indian ocean and the contribution rate is 57% and 30% respectively, while the water vapor in the South China Sea and the Western Pacific Ocean are dominant during autumn, with 45% and 37 % ratio. the upper level and low level circulation system between summer and autumn differ the characteristics of typhoon water vapor transport. Hainan island lies on the southwest edge of the Western Pacific Subtropical High during summer time, and the water vapor from the South China Sea and the Bay of Bengal-Indian Ocean is abundant combining the effect of the low pressure in the Bay of Bengal. While the center of subtropical high is east and the ridge line was south in autumn, the water vapor affecting Hainan Island mainly comes from the western Pacific Ocean.