Abstract: Streptococcus mutans（S.mutans） is known as a primary pathogen of dental caries, and its exopolysaccharide synthesis, adherence to tooth surface and biofilm formation is important physiological and virulence factor of S.mutans. High temperature requirement A（HtrA） is a periplasmic heat shock protein, which reduces the ability to withstand high temperature, extreme of pH and oxidative stress. This article reviewed the relationship between HtrA and virulence factors of S.mutans.