Objective To investigate the in vitro effect of xylitol on the proliferation and acid production of oral Candida, and so as to explore new prophylaxis methods against oral fungal infection. Methods Pathogenic oral Candida were clinically harvested, cultured and purified in laboratory from the saliva of 100 patients wearing dentures. The proliferation and acid production of 4 types of commonly-seen Candida albicans (C.albicans), Candida glabrata, Candida tropicalis and Candida krusei, were observed in Sabouraud’s glucose medium, with glucose replaced by different concentrations of xylitol (ratios of glucose and xylital being 41, 32, 23, 14, and 05), so as to evaluate the inhibitory effect of xylitol on the growth of different kinds of Candida. At the same time, the proliferation and acid production of C. albicans were compared when cultured with different concentrations (5%, 10%, 15%, and 20%) of xylitol (experimental groups) for 6, 12, 24, 48, and 72 h under aerobic and anoxic conditions. Results The D₆₀₀ values of four kinds of Candida in pure xylitol culture media were significantly lower and pH values were significantly higher compared with those in the glucose combined with xylitol culture media (P<0.05). Under aerobic condition, compared with the group without xylitol, the pH values in the experimental groups with different concentrations of xylitol were significantly higher and the D₆₀₀ values were significantly lower (P＜0.05), except for the D₆₀₀ values at 48 and 72 h with 5% xylitol, D₆₀₀ value at 48 h with 10% xylitol, and pH value at 48 h with 5% xylitol. Under anoxic condition, D₆₀₀ values were all significanlty increased and the pH values were all significantly decreased at all time points in the experimental groups (P＜0.05). Conclusion Xylitol can significantly inhibit the proliferation and acid production of the four common Candida species, suggesting that xylitol may serve as a substitute of sugar and inhibitor of pathogenic Candida and may play an important role in preventing and controlling oral infections of pathogenic Candida.