Abstract：In present engineering design，rock mass is simply treated as isotropic material and their strength parameters is given by decreasing those of intact rock through joint connectivity，which is introduced to reflect the integrity of rock mass separated by joints. This method may be acceptable for shallow rock engineering. But for deep rock engineering，with the increase of exploit depth，the anisotropic properties of rock mass become stronger and should be considered. In the previous studies，by defining joint connectivity as a scalar valued ODF(orientation distribution function) in microplanes，and based on Mohr-Coulomb failure condition and anisotropic strength criterion for jointed rock mass，a two-order fabric tensor of joint connectivity was proposed. In the study，the anisotropic criterion for jointed rock mass is presented briefly. The elastic stability problems of wellbore are studied according to the anisotropic strength criterion. When the anisotropic strength of rock mass is considered，the analysis show that drilling along the maximum in-situ stress may not be always safer than that along other direction at a given mud pressure.
