Using video games to support science learning has gradually grabbed much attention of educators and researchers and evidence shows that its positive impact on science learning seems promising. However, most of the available evidence always focuses on students’ learning through serious educational game (SEG) play, research that emphasizes pre- and in-service teachers’ perceptions and implementations of using SEG or their professional development through designing an SEG is still lacking. People, especially teachers, always consider creating a game-based learning environment to be expensive and arduous, which makes it become more challenging and difficult for them to integrate SEGs into science classrooms. Therefore, we delivered a 4-month curriculum for 12 students who are enrolled in teacher program. In this class, students learned Adobe FlashTM and programming of ActionScript 3.0 and were asked to really develop an SEG by their own. They were required to present their whole game idea and script in the midterm and demonstrate their game in the final. Data that focused on their professional development was collected via 3 interviews (at the beginning, middle and end of the semester). This chapter consisted of three sections. The first section briefly discussed the theoretical framework underpinning this study. Then, a brief introduction of the details of the curriculum including how it was designed and implemented was provided. Finally, the major part of this chapter particularly reported the obtained results about the professional development of these pre-service teachers who completed the curriculum and finished designing their own SEGs.