Abstract: Based on the engineering geological investigation results of Jinfeng Gold Mine in Guizhou Province,the RMR method is used to evaluate the rock quality in E3 section in 270 m and 290 middle sections of the mine from the six aspects of rock integrity,uniaxial compressive strength,joint spacing,groundwater state,joint state and the influence degree of joint occurrence to engineering construction.The study results show that:①the overall rock quality grade is Ⅳ level,the rock quality is poor;②the two groups rock mass structural planes with 2° tendency,54° inclination angle and 180° tendency,72° inclination angle are the weakest structural planes in the mining area,which affect the rock quality stability seriously,therefore,during the construction of mining engineering,the above directional structural planes should be avoided.

Key words: Gold mine, Engineering geological investigation, RMR rock quality evaluation, Weakest structural plane, Uniaxial compressive strength