The purpose of this study is to investigate the relationship between school climate(principal leadership and collegiality), teacher trust(teacher trust in the principal and teacher trust in teachers), and teacher efficacy in Korean middle schools. To accomplish this purpose, this study set up the specific questions as follows: a) To examine the relations of principal leadership, collegiality, teacher trust, and teacher efficacy; b) To examine the causal relations between principal leadership, collegiality, teacher trust, and teacher efficacy. Data were
collected from 233 teachers(male: 58, female: 175) who worked in middle schools in Seoul and Kyeonggi. The data from the test were analyzed in correlation, regression, and path analysis using SPSS 12.0 and AMOS 4.0 programs. To analyze the relationships among school climate, teacher trust, and teacher efficacy, structural equal modeling was carried out. The mediation
model posits that teacher trust mediate the linkage between school climate and teacher efficacy. Although both teacher trust in the principal and teacher trust in teachers were important links to teacher efficacy, principal leadership and teacher collegiality didn\'t directly related with teacher efficacy. In addition, both principal leadership and teacher collegiality promoted both teacher trust in the principal and teachers. The AMOS output showed that the
full mediation model was better than the other model.