The invention is directed to a calcium phosphate complex and the composition containing the same for oral care applications, in which the calcium phosphate complex is formed by chelating the γ-polyglutamic acid (γ-PGA) with amorphous calcium phosphate (ACP). This complex can prevent crystallization of ACP and maintain its high solubility. The calcium phosphate complex has superior mucoadhesion properties, allowing it to remain in the mouth longer and offering effective buffering, by which dental caries can be alleviated and prevented.