Abstract: The present situation of environment in the Region of Beijing, Tianjin and Tangshan is the result of human activity in the historical periods.Especially since the Jin Dynasty, the human effects on the nature had become stronger and stronger, the environmental problems ap-peared in a vicious circle.This paper is to explain the process and interrelation between popu-lation and landuse and try to find some laws that are useful to the improving of the regional environment.There are folloving two main parts in the paper:Ⅰ.Population research:In the Jin Dynasty, population increased acceleratively;in the Yuan and Ming Dynasties(A.D. 1276-1644), population increased with a sustainability;from the Qing Dynasty to the Republic Period, the population increased greatly. Ⅱ.Research on the landuse process in the region.Reclaiming wasteland and growing food grains by garrison and peasants appeared in the Jin Dynasty and reached its climax in the Ming Dynasty.According to the interrelation analysis between the population increase and cultivated area, it is concluded that theyfollow a linear equation(before A.D.1796):y=522+5.24x(y:cultivated area, x:population).The equation means that population and cultivated area increase with a similar rate.

Key words: Region of Beijing, Tianjin and Tangshan, Human activity