The purpose of this study is to analyze some institutions/systems in advanced countries designed to improve the quality of assembly-initiative legislation and thereby find more relevant institutional arrangements in Korea. We have found some common characteristics of such legislative systems that guarantee the quality of regulation: 1) close collaboration and two-way communication between the National Assembly and the government 2) a faithful legislative support mechanism 3) a credible review of assessment devices and 4) the transparent legislative process. In conclusion, we suggest ways to upgrade the quality of assembly-initiative legislation in Korea such as the provision of screening process and the guidelines for evaluating and designing better regulations.