Based on a study of elements distributed in Pb-, Zn-, Ag-related sedimentary formations within Mesoproterozoic Guandaokou Group and Upper Proterozoic Luanchuan Group in southwestern Hanan area, the supergene enrichment of these elements, and the distribution characteristics of integrated geochemical anomalies, the authors hold that Guandaokou Group and Luanchuan Group are Pb, Zn, Ag source beds, and that Longjiayuan Formation, Nannihu Formation and Meiyaogou Formation seem to be favorable horizons in search for stratabound Pb, Zn, Ag deposits related to such sedimentary formations as carbonate rocks of Guandaokou Group and clastic rocks-carbonate rocks of Luanchuan Group.