The authors are developing an effective design and construction system for underground rock caverns based on the monitoring of EDZ (Excavation Disturbed Zones). In this paper, AE (acoustic emission) was chosen as a measure of stress change in the rock mass around underground caverns. By using the PFC^2D code to represent rock mineral grains by discs, we simulated the AE behavior under changing stress conditions in laboratory tests. Furthermore, relationships between in-situ AE behavior and stress paths during a cavern excavation were established and a fundamental study on the estimation of rock mass behavior based on field AE monitoring was carried out.