Abstract: Several kinds of indexes representing the engineering quality of rock mass in mines were acquired by the survey of engineering geology and the measurement of crustal stress and field stress in Jinchuan No.3 mine area.After analysis,the jointing space,RQD,groundwater,structural plane attitude and uniaxial compressive strength of rock were selected to establish the assessment model of collapsihility.Based on this model,RMR and uniaxial compressive strength of rock,the parameters needed by Mathews stability graph approach were calculated.By using these parameters and the calculation method of stability number in Mathews stability graph approach,the stability number of each study area was calculated.Then,with the stability number,the hydraulic radius of sustained caving in each study area could be calculated by Mathews stability graph.It was shown through the analysis of the calculated results that these areas were suitable to be mined by the block caving method.