The present paper aims to study the relationship of organizational trust, organizational culture with knowledge sharing behavior among teachers of Second Intermediate Period in the City of Isfahan. Research method was correlation and statistical population included all teachers of Second Intermediate Period of Isfahan in academic year 2013-2014 (N = 3016). Sample size was 340 people according to Krejcie and Morgan Table (1970). Sample members were selected by multistage random sampling method. The required data were collected using 3 questionnaires. The collected data were analyzed by descriptive statistics (mean, standard deviation, frequency and percentage) and inferential statistics (Pearson correlation coefficient, stepwise regression, and regression-enter). The findings of this study showed that organizational trust and organizational culture have a significant relationship with knowledge sharing behavior (p<0.01). According to the results of stepwise regression analysis, in the first step (trust between employees), in the second step (mission) and the third step (organizational trust) have the ability to predict the behavior of knowledge sharing. Results of regression-enter analysis showed that trust between employees and organizational trust, of the three components of trust, and mission, among the components of organizational culture, can significantly predict knowledge sharing behavior (p<0.01).