Taiwan’s democratic education researchers are used to using the method of theory analysis and quantity analysis, but seldom focus on the practice of curriculum and instruction in the classroom. However, it is important for us to understand the democratic education operations through exploring the complexity of curriculum development and teaching practice in the classroom. The aim of this study is for the researcher, an upper-grade teacher of an elementary school, who employ self-study and teaching research to improve democratic education of social studies curriculum in the classroom that help students become citizens who can negotiate with others and respect diversity. The main conclusions are: (1) Democratic education of social studies curriculum can be improved when the self-study teacher sets an example of democracy; (2) It can help students to acquire the knowledge and skills of democratic education of the social studies textbook when teacher presents students with examples of real-life scenarios ; (3) Using self-study research on democratic education can broaden, deepen, and integrate other disciplines; (4) It would help students to discuss social issues by sharing life experiences.