Abstract:National Southwestern Associated University was a prestigious institution of higher learning resulting from the temporary forced merger of Peking University,Tsinghua University and Nankai University during the Anti-Japanese War.When the three universities first merged to form Changsha Temporary University,they started running the university together,and continued to do so when they later moved west to Kunming until the victory of the war.In fact,there were actually possible risks of separation and independence due to the forced merger of the schools.From Changsha period,to Mengzi period in Yunnan province,and then to the process of running the school in Kunming,the unity of the university was at stake on several occasions:some people suggested breaking up when the president did not arrive for his job;people from Peking University believed the university authority favored people of Tsinghua University;the university verged on separation when MEI Yi-qi intended to resign;the three universities requested the Ministry of Education to allocate funds to them respectively,which was also a prelude to separation.Fortunately,National Southwestern Associated University stayed united throughout the war despite all these twists and turns.The reason behind this is that the university had wise and patriotic intellectuals,trustworthy,modest and collaborative principals,and the safeguards of the Ministry of Education to maintain joint running of the three schools.Besides,it also learned a hard lesson from the separation of other associated universities such as National Northwestern Associated University.