This study has the purpose to identify the effect of problem based learning (PBL) in enhancing student's environmental literacy. This research used quasi experimental design. It involved 50 students from first grade of 10 th state senior high school of Semarang. The Students in experimental class was taught by problem based learning model while in control class was taught by conventional model. Data collected in this research was students environmental literacy who collected by middle school environmental literacy survey (MSELS). MSELS instrument first validity by rash analysis. The data gathered then analyzed using covariate analysis (ANCOVA). The result of this study showed that there are differences between PBL class and conventional class in enhancing student's environmental literacy with significant value as 0.002. This result indicated that PBL model could strength student's environmental literacy well.