Abstract: Objective　To evaluate the effect of static magnetic field on expression of bone morphogenetic protein-2(BMP-2) in the periodontal membrane of experimental periodontitis rat.Methods　Experimental periodontitis of rat was formed by ligaturing the neck of rat teeth and feeding sugar of high concentration. The magnetwhich the intensity of magnetic field was 0·12 tesla was put intotheir cheeks. The ratswere sacrificed at 2ndday, 4thday and 7thday, respectively. Immuno-histochemical techniqueswere used to evaluate the change of BMP-2 expression.Results　BMP-2 was mainly found in the plasma of fibroblast, osteoblast, ce- mentocyte and odontoblast separately. There was not clearly difference between the periodontitis group and the normal group, but BMP-2 in the experimental group treated with static magnetic field was higher than the two groups.Conclusion　Static magnetic field plays an important role in repairing and remodeling of periodontitis.

Key words: static magnetic field, bone morphogenetic protein-2, periodontitis