A total of 625 children, 3-4 yr old, 426 from Connecticut Head Start programs and 199 from Beijing area nursery schools, were clinically examined for dental caries. Results were analyzed using the traditional dmfs index as well as a new "Caries Analysis System". This new system differentiated between caries patterns and examined the percentage of affected children (Prevalence), the degree to which these children were affected (Severity) and the proportion of total caries each disease pattern represented (Distribution). The Caries Analysis System revealed differences in caries experience and patterns among the racial/ethnic groups that the dmfs index did not. The Beijing children experienced the greatest Prevalence of all caries patterns; however, the Severity and Distribution of the caries patterns were similar to those of the Connecticut children. Within the group of Connecticut children, White children had the lowest Prevalence but the greatest Severity when compared with the Black and Hispanic children.