Abstract: The rapid development of large cities at home and abroad in a large extent depends on the adequate supply of labor, and it is crucial for these cities to develop suitable population development strategies and policies. This paper presents a method used to making scenario simulation of population growth, which is based on Cohort component projection model and innovatively takes working-age population as a crucial variable, and then, to estimate the development trend of resident population in Shanghai. Results show that the population of migrant working-age will play an important role in Shanghai’s future development; therefore, immigration population of Shanghai should be given more attention and affirmation. This method is not only applicable for megacities which share characteristics with Shanghai in population age structure and growth trends, but also has suggestive meanings for smaller cities.