Abstract: An elastic-plastic Orthogonal inversion apprach is established according to the principles for testdesign on orthogonal Latin square to determe the stiff and strength paramerers on the basis of measured displacements around a mining stope. The parameters of the rock surrounding the stope for mining the gold-bearingbackfill in xiangxi Gold Mine are determined by combining the approach with FLAC. As a result, this has laida good foundation on which numerical modelling could be used to make safty assessment for the mining system.