We examined the transplanted bone marrow-derived cell migration into periodontal tissues. Bone marrow cells from green fluorescent protein (GFP) transgenic mice were transplanted. The immunohistochemistry (IHC) revealed that GFP-positive cells were detected in the periodontal tissues. The GFP-positive cells histopathologically differentiated into some cell types. The fluorescence IHC and TRAP staining techniques demonstrated these cells were detected as osteoclasts and macrophages. Furthermore, GFP-positive cells gathered adjacent blood vessels. The data suggest that GFP-positive bone marrow-derived cell migrate into periodontal tissues and differentiate periodontal tissue component-cells.