关羽北伐是对《隆中对》思想实践的产物 ,失在时机的选择不当和退却不及。但刘备缺乏权变 ,丧失了对荆益二刘的取代先机 ,蜀汉汉中、东线、关羽三路军队未能统筹策应 ,诸葛亮前期不甚为刘备倚重 ,联盟破裂 ,是关羽北伐毁败的重要原因。随即刘备夷陵战败 ,诸葛亮治国的思想不得已由“跨有荆益”嬗变为渐取陇右、蚕食雍凉、东和孙吴的务实方略 Guan Yu’s Northern Expedition was the product of the practice of thinking in “Long Zhong Pairs”, and the improper choice and retreat of the missing opportunity failed. However, Liu Bei lack of contingency, lost the opportunity to replace the two Liu Jing, Shuhan Hanzhong, east, Guan Yu Army failed to co-ordinate the response, Zhuge Liang did not rely heavily on the initial Liu Bei, Union rupture is the importance of Guan Yu Northern Expedition the reason. Immediately after the defeat of Liu Bei Yiling, Zhuge Liang’s thought of administering the country was forced to evolve from a “cross-Jing Yi” into a pragmatic strategy of gradually gaining control over Yong Long and encroaching on Yong Liang, the East and the Sun Wu