Abstract: With the speed up of population aging, Chinese family burden for the aged supporting are increased. Analysis the population size, age structure and developing trends of the elderly who can not take care of themselves is the basis of the study of the problem of aging. This paper uses the data of 1% population census and CFPS 2010 of Peking University to study the situation and characteristics of the elderly who can’t take care of themselves. Through the computer micro-simulation model of family parent-child structure, to predicts the population size and structure of the elderly people who can't take care of themselves in the future. The main results is, the total number of elderly people aged 60 and above who can not take care of themselves was 5.76 million, accounting for 2.60% of the elderly population, increased of 531.4 thousand compare to 2010. In 2015, there were 3.05 million elderly people without spouses living independently in China, increased about 11% over 2010. Among the male elderly who can't take care of themselves, the proportion without spouse is more than one-third, reaching to 37.72%, while that of the female elderly who can't take care of themselves is close to two-thirds, reaching to 64.48%. The total population of elderly who can’t take care of themselves in China will exceed 14.5 million in 2050, more than 2.5 times that in 2015. In 2015, the total population of the elderly without children and unable to take care of themselves is about 213 thousand. It will reach about 1 million in 2050, and the population size will be more than four times that of 2015. In 2015, the population of elderly people with one surviving child who can not take care of themselves exceed 1 million. It will exceed 5 million by 2050, which is more than five times of 2015.