Abstract: Water vapor is an important factor influencing the intensity of typhoon precipitation, and therefore finding the sources of water vapor is physically important in understanding the formation of heavy precipitation processes produced by typhoons. To investigate the water vapor sources for heavy precipitation in Shanghai (process precipitation≥50 mm) produced by typhoons, the hourly ERA5 reanalysis data is used to drive the HYSPLIT trajectory model to quantitatively explore refined source areas during the process. Three types of typhoons that have caused heavy precipitation in Shanghai over the past 20 years with different paths are analyzed, including: landfall type, nearshore-northward type, and Northwestern type. The results show that heavy precipitation produced by landfall typhoons has one major water vapor trajectory from the east. The major source area on the trajectory is the west of the Northwestern Pacific Ocean, with a water vapor contribution of 39.6%. Heavy precipitation produced by nearshore-northward (northwestern) typhoons has two (three) major water vapor trajectories from the east and the south (the east, the south, and the north). The major source areas on the trajectories are the west of the Northwestern Pacific Ocean, the South China Sea and the ocean east to the Philippines, and the southeastern coast of China, with water vapor contributions of 29.8% (18%), 18.5% (17.3%), and 23% (23.1%), respectively. We further identify the altitude layer and time period of each water vapor source area that contributes most significantly to the precipitation. The water vapor located at 950-925 hPa, 925-850 hPa over the west of Northwestern Pacific Ocean, 950-850 hPa over the southeastern coast of China during 15-168 h, 9-129 h, 3-48 h before the occurrence of heavy precipitation, contribute most significantly to the heavy precipitation in Shanghai produced by landfall, nearshore-northward, and northwestern typhoons, respectively. The study can provide valuable references for precipitation intensity forecasts of typhoons with different paths influencing Shanghai.