Abstract: With the increasing of the mining depth in Jiaojia Gold Mine，the joints and fractures of the rock mass are more developed，and mostly comprise unstable broken rocks；thus，in order to assure the production safety in the mine，determining the most reasonable stope span parameter is imminent.In this paper，by means of 3GSM， borehole camera and sonic wave testing，then statistically analyzed the properties and characteristics of the rock mass discontinuity;utilizing discrete element numerical calculation method to determine the optimal span for Jiao Jia gold mine′s upward level approach filling method which is according with the practical situation.At the same time，the research method of this paper also has reference significance for other similar mines.

Key words: Fractured rock mass, Stope span, Stope stability, Discrete element, Numerical simulation