古代北方的游牧民族，往往利用秋高馬肥時南侵，農業文明國家為此增加軍對防守，稱為防秋。本文主要是探討金代末年，在北方蒙古的強勢威脅下，金朝的防秋措施為何、及其侷限與付出的代價。
The ancient nomads of Northwest China often invaded China in the fall. There fore Chinese governments usually increased the military for defense on the season, called as fang chiou. This article is to explore the fang-chiou's measures, limitations and the price paid on Jin Dynasty.
