Abstract: From the viewpoint of ecological theoretics, the author defines the population carrying capacity of ecosystem as the maximum population amount healthfully sustained by ecosystem when its structure and function remain undistructed. This amount was controlled by the quantity of food energy produced by ecosystem and the ways human beings consume these foods. Mathematical method for the quantitative rescarch of ecosystem’s population carrying capacity was given, by which, a scientific population target could be suggested for the controlling of population.

Key words: PAHs, Adsorption, Biodegradation