Purpose: To describe the caries status and oral health-related behaviors of three- to five-year-old Chinese children by their ethnic background, and to identify potential determinants of caries experience. Materials and Methods: A cross-sectional survey was undertaken in a multi-ethnic province (Guangxi) in Southern China. Representative samples of preschool children from two ethnic groups (Han and an ethnic minority Zhuang: 487 Han and 470 Zhuang children) were examined using decayed, missing, filled teeth/surface (dmft/dmfs) indices. The children's general information as well as their personal oral hygiene practices and dietary habits were collected based on a structured questionnaire. Results: Overall, 60% of children had caries with a mean dmft value of 3.01. Zhuang children had a significantly higher prevalence of rampant caries (13% vs. 9%), mean dmft (3.36 vs. 2.66) and mean dmfs (5.10 vs. 3.76) than the Han children. Decayed teeth/surfaces dominated the dmft/dmfs indices for both Han and Zhuang children. Multiple regression analysis showed that ethnicity and drinking fruit juice from feeding bottles during babyhood were significantly related to dmft. Conclusion: There was a higher level of caries experience in the Zhuang ethnic minority than in Han preschool children. Keywords: dental caries, ethnic groups, oral hygiene practice, dental behavior