Abstract:One of the most prominent characters of subsea tunnel is that there is enriched water body because of the infinitude of the ocean above. There are mainly about two seepage problems induced by subsea tunnel excavation:one is determination of seepage pressure,another is the water inflow. Isotropic continuum medium model is adopted to analyze these two problems mentioned above. The essential of water pressure is studied;and conclusions are drawn. According to the latest research,some analytical models which are based on steady-state groundwater inflow into a drained circular tunnel in a semi-infinite aquifer connected with water pressure and water inflow are compared. The subsea tunnel in Kiaochow Bay is taken as background of the study. The influence of stress filed on seepage field is studied;and the effects of changes of surrounding rock permeability coefficient,water depth,permeability coefficient and thickness of grouting ring are analyzed which can be adopted for this particular project. According to the research,the pore water pressure and water inflow induced by tunnel excavation can be hardly affected by arching effect. Without consideration of fluid-solid coupling effect,if keeping the water level above horizontal plane fixed,the distribution of pore water pressure will not change with permeability coefficient of surrounding rock. The water inflow increases with the change of permeability coefficient of surrounding rock or water depth above surrounding rock. Both the decrease of permeability coefficient and the increase of thickness of grouting ring can reduce ground water inflow,but there exists an optimal value in grouting parameters. In practice,the decision should be made carefully between economy and bulkhead effect to confirm the optimal grouting parameters.