Abstract：Through the two aspects of geometry and mechanics，stability of rock mass is influenced by discontinuities. Therefore，connectivity research of discontinuities in jointed rock mass is analyzed at two aspects：(1) geometrical connectivity reflecting hydromechanics of rock mass and spatial orientation effect of discontinuities；and (2) mechanical connectivity reflecting strength of rock mass；thereby engineering properties of discontinuities are more disclosed generally. In the paper，discontinuities in the jointed rock mass are measured by means of surveying line sampling method，and orientation and trace length of discontinuities are corrected and Mote-Carlo simulated，thus the discontinuities' network models are formed. Then the network models are analyzed and calculated，therefore geometrical connectivity is acquired；and prevailing discontinuities are found through discontinuity network model. Based on the prevailing discontinuities，a method is presented to perform persistence analysis by coupling these prevailing discontinuities with other random discontinuities. And according to the rock-bridge failure theory，shear paths with minimum shearing force are searched by using dynamic programming，then reasonable mechanical persistence ratio of discontinuities，which is more conformed to the engineering practice，can be achieved based on this method.
