中国老年社会追踪调查（China Longitudinal Aging Social Survey，CLASS）

CLASS is a large-scale nationwide social survey project directed by NSRC. By collecting social and economic data of the Chinese aging population regularly and systematically on both individual and community level, CLASS aims at understanding various problems and challenges that Chinese people would face during the aging process, and evaluating the real effects which various social security policies have achieved in improving the life-qualities of the older population so as to provide important theories and factual basis to deal with aging problem in China.