A non-viral transfection method for oral mucosal cells was investigated using a modified transfection method and five commercial transfection reagents. The CellFECTIN(TM) gave the highest expression of a transfected gene. When the mucosal cells were transfected with 0.3 ng DNA/cell, the transfection efficiency was optimal, and the production of a reporter protein increased up to ten times higher than those with the other transfection reagents.