中文摘要：

中国疆域扩展经历了黄河与长江流域两大农耕区的联合、以中国北方农牧交错带为基点的疆域伸缩、突破北方农牧交错带三个阶段,地理环境不仅成为决定每个阶段的核心要素,且在制约人们经济生活方式的同时,影响疆域伸缩。其中年降雨量400毫米等值线所经地带,即中国北方农牧交错带在清以前各个时期,既是疆域变迁的回旋起落之处,也承担着起点与终点的双重角色,突破这条地理界限,将疆土持续而稳定地伸向大西北在清朝前期。

英文摘要：

There are three periods in the expansion process of China ＇s territory： the combination of the cultivation areas in the Yellow and the Yangtze River basins,the expansions and contractions of territory among the farming-pasturing interlocked areas in northern China,and territorial expansion beyond the farming-pasture zones. Geographical environment was the core factor in each of the three periods. Meanwhile,it restricted people＇s economic ways of life and influenced the size of territory as well. Regions along the 400 mm annual rainfall isolines,which were exactly farming-pasture regions,were the geographical base lines of territorial expansions and contractions before Qing Dynasty. In Early Qing Dynasty,China＇s territory finally broke through this geographical base lines,expanding towards north and west continually and steadily.