The studies at abroad mainly focus on operating mechanism, fund management, financial market conditions, successful experience and lessons in some countries, practicability of multi-pillar pension system mode in different countries and so on. The studies at home mainly concern about the research on its system and its related economics analysis, practice and feasibility of multi-pillar pension system mode, the coordinated development between different pillars, and analysis of a certain pillar on a certain special group. Foreign research achievement in this field is abundant, especially, the research results related to practicability of multi-pillar pension system mode provide beneficial reference for China’s reform practice and theoretical research, meanwhile, the relevant research in China should continuously broaden and innovate research scope and research methodology.