Model 1: Establish Logistic population growth model. Using the data in Annex 2 and the supplementary data of online search, the model is established according to three groups of total population data from 1954, 1963 and 1980 to 2005, and the prediction results are compared with those in Annex 1 Research Report on National Population Development Strategy. It is concluded that the model based on 1980 to 2005 has good prediction effect and good certainty. According to the total population data from 1980 to 2005, the total population of China is predicted to be10, 2020 and 2033 respectively.

Model 2: Considering the influence of population age structure on population growth, the model of women distributed by age (Leslie model) is established: based on the relevant data of 200 1 provided in Annex 2, the Leslie matrix is constructed and the corresponding Leslie model is established; Then, according to the population replacement rate 1.8 given by Chinese and foreign experts, the Leslie matrix is constructed and the corresponding Leslie model is established.

Firstly, the total population, working-age population and elderly population in China from 2002 to 2050 are predicted respectively (see Appendix 8), and then the development of the total population and working-age population in China is analyzed respectively with the predicted data, and it is concluded that the total population of China will reach 20 10/426.09 million in 2002 and 6,543.09 million in 2020. It is predicted that there will be no shortage of labor in China in the short term, but the adjustment of labor structure still needs to be strengthened.

Secondly, the problems of population aging and population dependency ratio are analyzed. It is concluded that the aging in China is accelerating. It is predicted that a peak platform for the elderly population will be formed in the middle and late 1940s, and the number of elderly people over 60 will reach 445 million, accounting for 33.277%. The number of elderly people over 65 reached 35,654.38 million, accounting for 25.53%. The population support is on the rise.

Thirdly, the population control in China is discussed, the number of women of childbearing age in the future and the number of women of childbearing age in the prosperous period are predicted, and the conclusion that the number of women of childbearing age will reach the peak in a short time and then decline is drawn.

Finally, the residual analysis, advantages and disadvantages evaluation and popularization of model ⅰ and model ⅱ are carried out respectively.