A variety of peer-related strategies have been explored in the decades, but similar terminologies and teaching steps of such strategies were different. Here we concentrated on Peer-Mediated Instruction and Interventions (PMII) and introduced its rationale, strengths, definition, and categories in this present article. Besides, four types of strategies and their steps were extracted from the evidence-based researches. For improving better performance of students with disabilities, we finally concluded few fundamental elements of PMII: training peers first, monitoring continually, providing feedback, and enforcement.