To evaluate the efficacy of Tooth Mousse in reducing enamel demineralization lesions adjacent to bonded orthodontic brackets and promoting remineralization in vitro.60 bovine teeth with bonded orthodontic brackets were randomly divided into three groups, negative control group, positive control group and experimental group, applied separately with distilled water, Duraphat fluoride varnish, Tooth Mousse. 3 groups were dipped into an artificial caries solution and an artificial saliva solution, cycling between them. All samples were detected by polarized light microscope, scanning electron microscope and electron probe micro-analysis.Polarized light microscope showed that the enamel surface of the experimental group were completed, the areas of positive birefringence were decreased obviously. Scanning electron microscope showed that a large number of deposits were found on the dental enamel surface of the experimental group, filled in the small local concave of enamel surface. Compared with the control group, electron probe micro-analysis showed that calcium and phosphate concentration of enamel surface was higher in experimental group than in negative control group (P0.05).Tooth Mousse can reduce enamel demineralization and promoting remineralization in vitro.