Based on data collected by the U.S. Bureau of the Census in its October 1980 Current Population Survey, this report examines school enrollment rates of 3- and 4-year-olds from three major ethnic groups (black, white, and Spanish origin) and relates this information to characteristics of the children's schools and households. Variables covered in the document's 10 tables include race or ethnic group, age, geographic region, metropolitan or nonmetropolitan location, family income, educational attainment of the household head and the mother, sex and occupation of the household head, mother's marital and labor force status, number of other children under 14 in the household, the school's educational level and public or private status, and the child's full- or part-time enrollment. Also noted is the impact of the federal Head Start program. Among the findings of the survey are that overall preprimary enrollment rates were roughly the same for whites and blacks but were lower for children of Spanish origin, and that blacks were far more likely than whites to be enrolled in full-day programs and in public schools. Two appendices present definitions of variables and discuss data sources and reliability. (RW)