Abstract: On the basis of the general stability theory, a disturbance response stability criterion for circular chamber rockburst is presented. The critical plastic softening depth and critical load of the chamber were obtained. It is concluded that the instability (rockburst) is an intrinsic attribution of rock chamber. As the external load on the chamber approaches to critical load, the chamber would lose its stability by small disturbance. The ratio of elastic modulus ?to descending modulus λ, E/λ, is an important parameter in rockburst analysis.