China is aging at an extraordinary speed and has the largest quantity of elderly persons in the world. Scholars utilize this unprecedented living experience of human being and the unique Chinese Longitudinal Healthy Longevity Survey (CLHLS) datasets with the aim to answer in this volume the following questions critical to the aging population world wide. Is the period of disability compressing or expanding with increasing life expectancy and what factors are associated with these trends in the recent decades? Is it possible to realize morbidity compression with a prolongation of the life span.