Abstract：Due to the limit of single index in the analytical method of sensibility，comprehensive assessment model of attribute recognition based on entropy weight of sensitivity is obtained. The assessment method including various appraisal indexes is used to the global analysis of the sensibility of constitutive models parameters. Also，the method for the sensibility of constitutive model parameters may give a new access. By combing with cohesion weakening and frictional strengthening of brittle rock mass，the assessment method mentioned above is used for the sensibility analysis of constitutive model parameters of surrounding rock mass in the auxiliary tunnel of Jinping II hydropower station. The results show that the main influence factors on deformation and plastic zone of surrounding rock mass are final internal friction angle，initial cohesion and elastic modulus；the next are residual cohesion，critical plastic strain of internal friction angle，initial internal friction angle and critical plastic strain of cohesion；the minor influence factors are Poisson¢s ratio and tensile strength. Based on the results，more attentions should be paid to final internal friction angle，initial cohesion and elastic modulus in similar positive and back analysis and studies in the auxiliary tunnel and diversion tunnel of Jinping II hydropower station.
