This study explored how secondary and elementary teachers perceive their science teaching using a half-structured, open-ended questionnaire. Teachers belief may relate to actual teaching practice in their classroom. Further, the current era is considered to be the era of post-constructivist teaching. To depict how proximate Korean elementary and secondary science classrooms are to constructivist teaching practice, we consider science teachers perception regarding the same as the first and crucial factor. The open-ended questionnaire helped understand their perception about the purpose of science teaching and role of teachers. The major keywords of school science, including content, context, constructivism, curriculum, curiosity, assessment, and inquiry were asked to describe as well. Total 9 elementary and 13 secondary level science teachers responded to the self-evaluation questionnaires. Most teachers believed that school science aims at knowledge acquisition and scientific thinking. Elementary and secondary level teachers considered the seven items of school science at the perceptual level. The difference between elementary and secondary level teachers perceptions are discussed in terms of teachers role as science professionals versus science educators.