Abstract: Dilokong Chromium Mine in South Africa is a high grade deposit and it is the typical gently inclined thin bodies，the room-and-pillar stoping mining method was adopted.According to the mining conditions of gently inclined thin Chrome ore body and current mining problem of Dilokong chromium mine，in order to get the reasonable structure parameters and achieve safe & efficient mining，the paper adopted orthogonal numerical simulation experiments，which selecting four parameters including room length，room width，pillar dimension and pillar spacing，and orthogonally designed nine feasible stope structure models with four factors and three levels.Through FLAC^3D simulation results comparing of stress status and surrounding rock displacement of different structure parameter schemes，the paper had studied influence of different parameters to stope stability and optimized stope structure parameter.The research result showed that room width and pillar dimension were the important influence parameters of stress concentration and displacement deformation，and the reasonable stope structure parameters were determined:the length of room is 50 m，the width of room is 26 m，the dimension of pillar is 5 m×5 m and the spacing of pillar is 2 m.The results will guide a significance to next mining of Dilokong Chromium Mine.

Key words: Chromium mine, Gently inclined thin ore body, Numerical simulation, Stope structure parameter