Abstract: By studying the relationship among the economy, environment and the living standard of Tianjin residents, a new dynamic standard function is constructed for the population carrying capacity, and then the dynamic model is established about the relationship among the population, economy and environment. Meanwhile, the conditions of population carrying capacity in Tianjin are analyzed. Finally, some measures are discussed to improve the population carrying capacity of Tianjin.

Key words: population carrying capacity, dynamic model, Tianjin area