This study demonstrated that streptococcus mutans could be inhibited completely after contacted with 0.1% CTP for 5 minutes. There were no drug resistance after repeat cultures in 0.025% CTP. Plaque Index and Gingival Index decreased significantly (P < 0.001) after 0.2% CTP were used to rinse and brush the teeth. Results proved that CTP is an effective agent to prevent dental caries.