The purpose of this study is to develop an integrated instruction model in primary schools by exploring the process of science theater in English. To accomplish the objective, the researchers set up a program which includes science experiments, drama games, and performance in English by primary school students. The data collected from diverse sources were analyzed using both quantitative and qualitative techniques. There were four results found from this study. First, the scholastic achievement both in Korean and English was improved. In addition, the students' interest and learning style influenced the test scores. Second, children in this study achieved real accomplishment through diverse student-centered activities. For example, they experienced accomplishment by getting over their mistakes in experiments, fostered a collaborative attitude through process-based tasks, and realized responsibility in their learning by leading their own learning. Third, students experienced a new type of integrated learning in English and science. In other words, they recognized English as a means of learning a subject and regarded science experiments as activities for exploring knowledge. They also considered science theatre as an opportunity for self-realization. Fourth, a model for integrating English and science in primary schools through science theater is presented. Finally, based on the results, the researchers provided several suggestions for future studies.