The present study aims to identify the effectiveness of summer science camp experience on middle school students' content knowledge and interest towards biology. For this purpose, two instruments including reflective journal and pre-post questionnaire were developed by four researchers who are expert in science education. Besides, the instruction was observed and students' field notes were taken during the camp by a graduate assistant. These instruments were administered to 48 students enrolled summer science camp which is referred to "Funny Discover of Mysterious World". However, only ten students were randomly selected for preliminary case study. The findings showed that students' understanding developed during science camp. However, their understanding is broadly partial and some of students have misconceptions. On the other hand, science camp had impact positively on their interests toward biology, their career decision and perception regarding biology and daily life.