Objective To investigate the effect of menthol compound decoction on the growth and acid metabolism of cariogenic bacteria and to find out the anticariogenic mechanism of Menthol compound decoction .Methods Streptococcus mutans ,Streptococ‐cus sanguinis and Porphyromonas gingivalis were chosen as the experimental bacteria .Firstly ,slip diffusion method was used to ex‐amine the inhibitory effect of menthol compound decoction on cariogenic bacteria .Secondly ,observing the effect of menthol com‐pound decoction of different concentration on acid metabolism .Results Menthol compound decoction could inhibit the growth of Streptococcus sanguinis and Porphyromonas gingivalis .And it also inhibited the acid production of cariogenic bacteria ,but the con‐centration of menthol compound decoction were different .Conclusion Menthol compound decoction may have an inhibitory effect on the growth and acid metabolism of cariogenic bacteria .