This book analyzes data from eight waves (1998, 2000, 2002, 2005, 2008, 2011-12, 2014 and 2018) of the Chinese Longitudinal Healthy Longevity Surveys (CLHLS) to explore how health status of the Chinese oldest old has changed over time and across birth cohorts. It also intends to investigate how period and birth cohorts have played a role in the associations between Chinese oldest old’s health and a variety of demographic, socioeconomic, and lifestyle factors. The book applies the age-period-cohort (APC) approach and constructs cross-classified random-effects models (CCREMs) to carry out the analyses. The oldest old’s health is measured by self-rated health (SRH), chronic diseases, cognitive function and subjective wellbeing which is indicated by positive and negative feeling scores. The results show that Chinese oldest old’s health status has changed over time and across birth cohorts. Significant period and cohort effects are shown when linking Chinese oldest old’s health to various demographic, socioeconomic and health lifestyle covariates. In general, period effects surpass the cohort effects. Particularly, the oldest old’s subjective wellbeing is more likely to be influenced by period than cohort effects. Period changes caused by social events, such as economic hardship and natural disasters, have left strong imprints on Chinese oldest old’s mental than physical health status. Based on these findings, the book highlights some important policy implications and points out future research directions to improve the current study. It provides an interesting read for researchers in gerontology and public health studies. It is also of interest to general audience, including practitioners in health care and policy makers who are interested in old age care and healthy aging policies.