Abstract: There are three major battles that SIMA Qian wrote in Records of the Grand Historian, namely, Changping Battle in the late Warring States Period, Chu-Han Battle during the Qin and Han dynasties, and Han-Xiongnu Battle in the Western Han Dynasty. Changping Battle was a major event at the turning point of historical changes when Qin and Han dynasties replaced Xia, Shang and Zhou dynasties. The nature of Chu-Han Battle was a civil war between Western Chu and Han, who were engaged in a struggle for supremacy over China. Han-Xiongnu Battle was a clash of civilizations that affected the world, which marked a conflict between the farming civilization in the south and the nomadic civilization in the north. The author tries to explain the battles from three aspects:causes, Sima Qian's description and practical significances of the battles.