Shanghai is facing big population risks: the population scale is expanding, exerting great pressure on natural resources and public services; the city is aging while the fertility rate is decreasing, causing heavier and heavier burdens on the working population; talented persons only account for a small share in the total population, not meeting the demand of socio-economic transition; inadequate distribution of businesses and public services brings about over-concentration of population in the downtown area. In order to meet such challenges, Shanghai's population strategy should conform to four "suits"： the population scale should suit the carrying capacity of regional resources, the population quality should suit the need of socio-economic transition, the population structure should suit sustainable development of the city, and the population distribution should suit the distribution of businesses and public services. As to detailed measures, it is suggested to improve population structure by improving industry structure, to promote population quality by promoting human-resources management, to optimize population distribution by optimizing the function of suburban new towns, and to seek population inflow-outflow balance by seeking innovations in social security policies.