The word "longevity" is sometimes used as a synonym for "life expectancy" in demography. However, the term longevity is sometimes meant to refer only to especially long-lived members of a population, whereas life expectancy is always defined statistically as the average number of years remaining at a given age. For example, a population's life expectancy at birth is the same as the average age at death for all people born in the same year (in the case of cohorts). Longevity is best thought of as a term for general audiences meaning 'typical length of life' and specific statistical definitions should be clarified when necessary.

In the present book, twelve typical literatures about health longevity published on international authoritative journals were selected to introduce the worldwide newest progress, which contains reviews or original researches on health longevity. We hope this book can demonstrate advances in health longevity as well as give references to the researchers, students and other related people.