In Israel, efforts to narrow the cognitive and social gap between pupils have been directed toward integration through structural changes in the educational system, along with expected changes in the educational process. This study analyzes the relationships between the school climate and the different educational outcomes for students in various class situations. The study is based on analysis of data from a Junior High School study which was aimed at evaluating the reform in the Israeli educational system, and the conclusions of a case study of five integrated junior high schools in Israel. The ethnic composition of the classes studied varied due to the specific demographic situation in each area, to the location, and to individual school policy. It was hypothesized that school climate may have a differential effect for different types of classes, according to their composition and grade. On a school level analysis, two distinctive climates were revealed: an achievement-conservative one and an integrative-open one. The type of climate was related to various student variables, such as achievement, aspirations, locus of control, self image, and anxiety. Results showed that classes are differentially sensitive to the effects of school climate, according to their ethnic composition. Also, in analyzing "extreme school climate situations," the potential impact of school climate was found to be quite consistent. It is suggested that school climate is a dynamic phenomenon, changing through an interactive process, having different effects on different classes and with different situations. (Author/AOS)