4D visualized tunnel construction monitoring system is developed by means of Open CASCADE 3D geometry engine and Visual Studio 2008, so as to facilitate the dynamic management and decisionmaking in tunneling. The mentioned system has been successfully used in the monitoring of Hongqihegou station on Chongqing railway transit line 3. Due to the application of the mentioned system, the tunneling conditions and the monitoring data are displayed rapidly and intuitively, which in turn guarantees the tunneling safety. 