Individual variability is one of the common features of aged human populations. As the popu- lation aging rate in Japan is forecasted to be over 40 % around 2050, physiological and patho- logical variability of aging is a rising big issue not only for medical scientist but also as social concerns. Such variability could be partly explained as consequences of human evolution, but decrease of death rates also facilitates it indirectly. Here we review on aging and anti- aging research in 21st century, which would play a significant role to dissolve the problems relevant to the following issues. That is, regulation of aging, epigenetics, removal of senescent cells, regeneration of the tissues, and environmental improvement.