Abstract: The random discontinuity plane，structural plane and weak plane in rock mass will reduce the strength of rock mass and weaken the stability of rock mass. The research work of rock mass structural plane can lay the foundation for clarifying the mechanical parameters of rock mass and classifying and zon⁃ ing the stability of rock mass. Based on the rock mass of stope slope in No.2 Mine of Kunyang Phosphate Mine，the structural plane of rock mass was investigated by detailed line observation method，pole density map method and stereographic projection map method，and the influence of rock mass structure on the sta⁃ bility of stope slope was analyzed. The results show that the structural plane of the slope rock mass in the mine is relatively developed，mostly steep type，and mainly closed joints. The failure mode of the structur⁃ al plane distribution on the stope is mainly spalling and roof caving.

Key words: structural plane of rock mass, pole density map, stereographic projection map, rock mass stability