First, spatial expanding process of Beijing and Tianjin is analyzed, then, influential factors motive mechanism and growing trends have been pointed out. Base on this, suggestion for improving spatial integration of Beijing and Tianjing is proposed.

• 本文首先分析了北京、天津二市的空间扩展过程 ,指出了其扩展的影响因素、动力机制及发展趋势 ,在此基础上 ,进一步提出了促进京津空间一体化的建议。