By adopting the AECI Index Method proposed by the author and using method of population simulation,this paper analyzes quantitatively the trend,intensity and regulation of the economic pressure of population ageing in China,and compares China with other countries.It draws the following conclusions:(1) China will face great economic pressure due to population ageing in the first half of this century.According to the medium projection,the pressure will increase most rapidly during the period from the middle of 2020s to the end of 2030s,and reach its peak around 2040 when the intensity of the pressure may quadruple that in 2010.(2) The great economic pressure of population ageing may remarkably reduce China’s development momentum.(3) To ease the pressure,we should rely mainly on economic measures,supplemented by population control measures.(4) To gradually liberalize the prevailing birth control policy on the premise of sticking to the state policy of family planning is a rational approach to regulate the economic pressure of population ageing in China.On the one hand,this can ease the possible economic pressure of ageing in the future,and on the other hand,it can control the pressure of population size within an endurable limit.