中文摘要：

秦汉帝国时期是中原王朝＂大一统＂局面形成的重要时期。北方匈奴是当时帝国在已知地域中唯一可以与之抗衡的政权。汉武帝即位后,双方进行了殊死决战。随着匈奴的败退,中原王朝将触角逐渐延伸到广大的西北地区。为巩固边防与对外征战,秦汉帝国对征服区域进行了大规模的农业开发,开发力度之深,影响之远前所未有。

英文摘要：

The period of Qin and Han Empires was an important period to form the＂Unification＂of the Central Plains. The Northern Hun was the only regime that could resist against the Empires in Northern China.After Emperor Wu Di came to the throne,he launched a war against the Huns,who were defeated and forced to retreat to the Northwest,and the power of the Central Plains was extended to the Northwest region. In order to strengthen national defense against foreign armies,the ruler of Qin and Han Empires carried out agricultural development in the occupied areas which was unprecedentedly thorough and influential.