Abstract: The water intrusion is a common problem in tunnels,especially in southern karst area.It affects the whole process of tunnel construction and operation.According to the survey data,1525-meter long(62% of total length of Zoumaling tunnel) karst sector(including fault fracture zone) is prone to water intrusion.This paper presented a preliminary prediction of water discharge,which may be caused by continued tunnel excavation,based on real-time discharge monitoring data of excavated tunnel and project surveys.The results provide guidelines for control of potential water intrusion.