Abstract: The 3D geological mapping in ore concentration areas adopts the 1:50000 survey scale and submits surface and deep geological maps with certain precision, which provides geological basis for the delineation of main geological targets like ore-bearing formation and ore-controlling structure. With the 3D geological mapping work in Benxi ore concentration area, the authors think that the structural mapping is the basis for 3D geological mapping. The authors also propose the 3D geological modeling method of "grading and blocking", and summarize the 3D geological mapping method and technique process in ore concentration areas.