Objective: To explore a new method for effective and safe prevention and treatment of caries. Methods: Following the theory of tooth remineralization, we searched for the mechanism and clinical application of tooth remineralization with phosphopeptide. Results: Phosphopeptide, with calcium and phosphorus, had a high affinity for hydroxyapatite and could enhance tooth remineralization. Conclusion: Phosphopeptide was effective in the prevention and treatment of tooth decay. Clinically, it could be safely applied.