Objective: To determine the inhibitory effects of maltitol-gum on Streptococcus mutans, Lactobacilli and Actinomyces viscosus in dental plaque. Methods: Thirty 13-15 years old children with DMFS>4 were divided into three groups, maltitol chewing gums group(A group), xylitol chewing gum group(B group) and blank gum base group (C group). The plaque samples were collected and colony forming units were counted. Results: The levels of three-species cariogenic pathogens in three groups were statistically down-regulated when compared with the baseline(P<0.001).Moreover, A group and B group resulted in a higher decrease of Streptococcus mutans levels compare with C group(P<0.05). The levels of Lactobacilli and Actinomyces viscosus were not statistically different between groups(P>0.05). Conclusion: Maltitol-gum can lead to a significant suppression on Streptococcus mutans levels in dental plaque,while the inhibitory effect of the maltitol-gum on Lactobacilli, Actinomyces viscosus is not obvious.