Objective: This paper was designed to confirm the efficacy of chewing carboxymethyl chitosan (CMCTS)-containing gum in suppressing the growth of oral bacteria when compared to a CMCTS-containing mouth rinse. Methods: Fourteen healthy subjects were recruited from among the staff and students of Qingdao University Dentistry Department. Before the experiments saliva was collected from all subjects and bacteria counts determined. For the gum study, the subjects chewed CMCTS-containing gum for 5 min and then rested for 5 min. When testing the CMCTS mouth rinse, the subjects gargled with 10 mL of solution for 30 s, followed by resting for 9min 30 s. These protocols were repeated five times over a 50 min period on the same day. Post-experiment saliva samples were then collected at the following times: 0, 30 and 60 min.Results: Chewing gum containing CMCTS or rinsing with a CMCTS-containing rinse significantly decreased oral bacteria counts. The total bacteria counts, total Streptococci counts, and mutans streptococci counts of saliva from subjects who chewed CMCTS-containing gum were significantly lower than saliva from subjects in the rinse group in all three sampling periods, except in the case of the total bacteria count in the 60 min samples. Conclusion: CMCTS-containing gum chewing has a greater antibacterial effect than using a CMCTS-containing mouth rinse. The present findings strongly indicate that the application of natural materials such as chitosan and its derivatives is useful for better oral health.