“Life increases age and the increase of age ends life”—This is the subtitle on front cover of the first issue of the world’s first Elderly Journal published in 1946. The “increase of age” that “ends life” has kept accelerating in the past 40 years. More gray-haired people are seen among street crowds，confronting mankind with a “silvery tide”—the aging of population—in addition to the rapid growth of population. Developed countries have been in the lead in becoming aging societies. Ever since the 1970s，when its fertilitv rate was dropping considerably，China’s age structure has been changing quietly from a young type into an adult type and towards an elderly type. Given the current age structure in the country，the aging process of China’s population is expected to proceed rapidly，exerting tremendous impact on the country’s economy and social development as well as the population itself. The major problem is how to deal with an elderly population that will be more than four times larger than the current one，and how to meet its basic needs.

The Institute of Population Studies under the Chinese Academy of Social Sciences undertook a survey of China’s elderly population and research on the social security of the elderly，a key project of the State Seventh Five-Year Plan. It also assisted the urban and rural sampling team of the State Statistical Bureau in completing in 1987 the sampling survey on China’s elderly population，in order to provide a theoretical basis for the relevant State policy，the reform and the establishment of a social security system for the elderly，and to prepare first-hand data for the country’s research on the elderly population.

The survey was conducted strictly according to the principle of random samplying. A second sampling was made in cities and townships on the basis of the first that involved 150000 households，with a tolerance of±0.5 percent. The survev covered 223 cities and townships，involving 17819 people more than 60 years old，and 830 counties，including 60，000 regularly surveyed households，with 18936 people over 60 involved. A total of 36755 elderly people were surveyed in the urban and rural areas in all the 30 provinces，autonomous regions and municipalities in the country except Tibet and Taiwan. The survey was made on a scale larger than any other of the same kind in the world，thus ensuring its value in deducing the general situation among the country’s elderly population.

Fig.1 Age Structure of the Chinese Elderly population in 1987

The standard time of the sampling was set on 12 midnight on June 30，1987 and the whole survey was completed within the period from July 1st to 15th. In order to ensure the survey’s quality，a trial sampling was conducted in Shanghai and Guangdong Province，and non-sampling errors were minimized through strict requirements in questionnaire design，interviewer training，form checking，compu-ter input，logic examination and final checking and acceptance. It was proved that the sampling survey in 1987 on China’s elderly population met the requirements of the designers with high quality and reliable data. Upon the basis of the survey’s first lot of data，this treatise analyzes the characteristics of the country’s elderly population and examines some of the most important factors that affect population，economic development and the reform of the social security system.