By using NCEP reanalysis data and WRF model, the water vapor transport process of long-range typhoon rainstorm was studied with a case in Shandong province during 17-19 July 2008. The results show that the typhoon circulation not only provides favorable conditions for water vapor transportation from the Western Pacific Ocean to Shandong inland area, but also affects the intensity and time duration of the long-range precipitation by changing the intensity and direction of the airflow from the Bay of Bengal. The contribution of water vapor from typhoon to the southeastern Shandong is much greater than that to the southwestern Shandong. Therefore, removal of typhoon circulation can indirectly enhance the water vapor supply to the southwestern Shandong. The typhoon circulation intensifies the long-range precipitation by contracting the water vapor convergence area and intensifying the convergence.