Abstract: Rock burst is increasingly becoming the dangerous disasters damaging to engineering safety，thus the establishment of an effective criterion to prevent this type of disaster is of great importance.Based on the Mohr-Coulomb strength theory，the stress indicators of impact risk deduced by analytic geometry method is proposed，and the criterion is verified by the triaxial tests of monzogranite rock sample.The research shows that:①The criterion of impact risk and its stress indicator has a good correlation with the rock stability.Specifically，the higher the value is，the higher the probability of impact risk is.②The stress indicator of impact risk can reflect the impact risk degree of rock under a certain stress level，which can comprehensively reflect the influence both of stress parameters and mechanical parameters on the impact risk，and compensate the deficiency of single-index analysis of the maximum principal stress，the minimum principal stress.③It can be employed as a new analysis indicator for the numerical method.The spatial distribution of the stress indicator obtained by numerical calculation is a direct reflection of the rock impact risk in different locations，which provides a predicting basis for rock-burst.

Key words: Rock burst, Strength theory, Impact risk, Criterion, Stress indicators