The current judicial reform in China aims at enhancing the professionalism and accountability of judges, and at the same time, at improving the people's assessor system to broaden lay participation in adjudication. The duality of the purpose of reform calls for a comprehensive analysis and discussion on the people's assessor system from the perspective of Chinese history and culture as well as comparative law. Historically, the concept of ″lay participation″ was adopted in China during the period of the Modern Democratic Revolutionwhen Western legal culture was introduced. It is the political symbol of the people's participation in justice, but has not well integrated into modern procedure law. From the perspective of comparative law, although it is literally called ″jury″, it embraces some features of the lay assessor system in continental law system countries while retaining some elements from Chinese traditional judicial culture although it is literally called ″jury″. Japan and South Korea initiated lay participation in criminal trials as a pillar of the judicial systems at the beginning of 21st century, which was an important development in Northeast Asian comparative law, The similarities in the institutional framework and legal culture between Japan, South Korea and China provide useful reference for the reform of China's people's assessor system. Therefore, it is necessary to carry out comparative study on the motivation of the reform, the content and the effectiveness of lay participation in the three countries. In terms of motivation, Japan and South Korea both aim to overcome bureaucratic deficiencies, such as lack of judicial transparency and inadequate social awareness in highly formal judicial decisions by high elite judges, hoping to gain public support of and trust in the judicial system. By comparison, China has stressed the importance of improving judicial professionalism while allowing ordinary citizens to participate more in the adjudication process. Although the three countries share common goals of reform, they differ in system and functional designs. The lay participation in China and Japan is in many respects closer to the model of lay assessors in those countries with civil law tradition, in which lay persons have equal power and obligation as professional judges. By contrast, Korean jurors are only allowed to decide the facts of the case and such decisions on the facts are only for the reference of the panel of judges when they make the final decision. The comparison with Japanese lay participation and Korean jury not onlydemonstrates the institutional similarities and differences, but also provides reference for the further reform of the people's assessor system in China. The primary goal of lay participation is to ensure and achieve fairness and justice in each case. The practice in Japan and South Korea indicates that it is the top priority of Chinese judicial reformers to balance the relationship between professionalism and lay participation, and meanwhile to ensure the goal of professionalism. It should also be realized that lay participation in adjudication is not the only possibility for ordinary citizens to be involved in judicial practice. The reformers should consider some other ways to involve lay persons in the review of prosecution, fact finding, etc. Moreover, it is also crucial in the future reform to weaken the political significance and strengthen the judicial function through the improvement of procedural rules on the court in order to meet the increasing demands arising from the practice and litigation in China.