Water inflow/bursting is one of the common disasters when tunneling under complex geological conditions, which may jeopardize the construction safety and the construction schedule. The causes and possibility of water inflow/bursting are analyzed in terms of the feeding, flowing, storing and pressure of the ground water, so as to accurately predict the water inflow/bursting in tunneling. Case study is made on the water inflow/bursting of several tunnels. Some items that may be ignored in geological investigation and prediction are listed on basis of theoretical analysis and engineering practice, so as to attract more attention.