This study initiates a discussion on the principles and methodologies for implementing successful multicultural classrooms. In doing so, this paper discusses three major characteristics of multicultural classroom, and proposes ecological perspectives to understand the idiosyncratic context and environments of multicultural classroom. Then, this paper suggests a participation model which consists of mediation, collaboration, participation, and embeddedness as four constructing principles. Finally, this paper provides three methodological approaches of practicing an effective instruction for multicultural classrooms; Differentiated Instruction, Culturally Responsive Pedagogy, and Interactional Feedback Approach for securing instructional counterbalance. The significance of the Participation Model for multicultural classrooms lies in the following three points. First, the leadership for learning belongs to students, rather than teachers; second, the interaction between students becomes maximized and contextualized learning of meaning is emphasized; and third, students will perceive that learning is the result of continuous experience, through which they can participate in and cooperate with the communities of inquiry. Discussions on these three methodologies are followed.