This report presents the findings of a statewide census of basic science curriculum data in the state of Illinois. This census, conducted in 1977, was designed to produce normative data relative to science course offerings, enrollments, and curricular activities in Illinois public secondary schools and to establish a data base on secondary school science curriculum. The report includes: (1) highlights summary; (2) interpreting the findings; (3) schools in the census; (4) the typical natural science program in Illinois high schools; (5) the typical natural science program in Illinois junior high schools; (6) the required high school natural science courses; (7) the required junior high school natural science courses; (8) enrollment in high school students by sex; and (9) enrollment in junior high school students by sex. (HM)