CSIRO has been conducting a five-year research project under the sponsorship of JCOAL and Ulan Mine to develop a real-time roof monitoring and roof fall warning system for underground coal mines. A preliminary system has been developed and successfully trialled twice in the gateroads at Ulan Mine during 2004 and 2005. The system integrates the displacement monitoring, stress monitoring and seismic monitoring in one package. It includes: • GEL multi-anchor extensometers • Vibrating wire uniaxial stress meters • ESG seismic monitoring system with microseismic sensors and high frequency AE sensors. The monitoring system has been automated and the data are automatically collected by a central computer located in an underground non-hazardous area. The data are then transferred to surface via an optical fibre cable. The realtime data can be accessed at any location with internet connections. The trials of the system in two tailgates at Ulan Mine have demonstrated that the system is effective for monitoring the behaviour and stability of roadways during longwall mining. The continuous roof displacement/stress data have showed clear precursors of roof falls. The seismic data (event count and locations) have provided insights into the roof failure process during roof fall. The sensor type and real-time communication system are flexible and can be tailored to meet site-specific monitoring needs.