The process of population agglomeration/shrinking and changes in spatial pattern are the most intuitive presentation of the spatial distribution of population. This study focused on the pattern of population agglomeration/shrinking and the overall population evolution trend. In view of this, we took the Beijing-Tianjin-Hebei Metropolitan Region as an example, based on 1982-2010 census data, using the degree of concentration of the population, population increase-decrease change, population migration methods, quantitatively studied the process of population agglomeration/shrinking and changes of spatial pattern in Beijing-Tianjin-Hebei Metropolitan Region. The study shows that the total population continues to grow, but rendering uneven growth in over different areas during nearly 30 years in the Beijing-Tianjin-Hebei Metropolitan Region. The regional distribution differences of population are obvious, especially between north to south, east to west of Beijing-Tianjin-Hebei Metropolitan Region. Population increase is a main character, more than 80% of the counties possessing a population growth, reflecting the effect of population concentration. Population decrease is just scattered, less than 20% of the counties possessing a population decrease. The population flow is more frequent in the Beijing-Tianjin-Hebei Metropolitan Region. Population flow into the region is located in the urban areas of Beijing, Tianjin and Hebei. Population outflow is mainly from the impoverished mountainous counties of Zhangjiakou and Chengde. Both the static demographic indicators and the dynamic analysis method show that the population agglomeration/shrinking and changes of spatial pattern are very obvious. The Beijing-Tianjin-Hebei Metropolitan Region has already formed the Beijing, Tianjin, Shijiazhuang and other cities as the centers, holding population flow from adjacent counties, i.e., presenting a multi-center structure of population distribution.