The purpose of this study was to compare the affective behavior of students enrolled in the various high school science courses. The sample for the study included eight science courses. The sample for the study included eight science classes consisting of the following: 45 ninth-grade Introductory Physical Science students, 46 tenth-grade biology students, 47 eleventh- and twelfth-grade chemistry students, and 52 eleventh- and twelfth-grade physics students. The instrument used to measure the students' affective behavior, the Affective Domain Measuring Scale (ADMS), was developed using Thurstone's techniques and the first four categories of the affective domain continuum published by Krathwohl in 1964. Mean scores were calculated from the students' responses on pretest and posttest exercises. The t-ratio was used to test for significance. The following conclusions were made: (1) the affective behavior of most science students changed in the unfavorable direction, (2) the high school science students enrolled in physics and chemistry have a more favorable affective behavior toward science than do the biology and Introductory Physical Science students, (3) physics, chemistry, biology and Introductory Physical Science students experience different amounts of change in affective behavior during one semester, (4) males have a more favorable affective behavior toward science than do females, and (5) females' affective behavior toward science changes more than males' affective behavior toward science in one semester. (Author/MLH)