Purpose: The aim of this study was to investigate the effects of EMD on demineralized root surface using human periodontal ligament cells and compare the effects of root conditioning materials(tetracycline(TCN), EDTA). Material and Methods: Dentin slices were prepared from the extracted teeth and demineralized with TCN and EDTA. Demineralized dentin slices were incubated at culture plate with 25, 50 and $100{mu}g/ml$ concentration of EMD. Cell attachment, alkaline phosphatase activity test, protein synthesis assay and scanning electronic microscopic examination were done. Results: Cells were attached significantly higher in EMD treated group at 7 and 14 days. Cell numbers were significantly higher in EMD treated group. Alkaline phosphatase activity was significantly higher in EMD treated group at 7 and 14 days. Protein synthesis was significantly higher in EMD treated group at 7 and 14 days. Conclusion: Enamel matrix derivatives enhance the biologic activities of human periodontal ligament cells on demineralized root surface and its effects are dependent on the concentration of EMD.