This study was designed to explore pre service elementary teachers' understandings of SE instructional model and the influence of their knowledge on their teaching practice. The sample consisted of 90 Turkish pre service elementary teachers (aged 18-24 years). The newly developed SE Test comprising two-tired 12 items was employed to collect the data. The data were also supported with pre service students' lesson plans. The results suggested that the pre service elementary teachers had problems about the phases of the SE model and they had weak understanding about enter, explanation and exploration phases and also their understandings are effective on their teaching practices.