国民军是原直系将领冯玉祥、胡景翼和孙岳在1924年10月发动北京政变后组织的一支军队，共有三个军。冯任总司令，胡、孙二人为副总司令，三人还分别兼任一、二、三军的军长。1925年1月冯玉祥被任命为西北边防督办时，将国民军一军扩 编为“中华民国西北边防军”，简称西北军。1 The National Army was an army organized by former direct generals Feng Yuxiang, Hu Jingyi and Sun Yue after the coup d’état was launched in October 1924 in a total of three forces. Commander-in-chief Feng Ren, Hu, Sun two deputy commander in chief, the three also served as one, two, three army commander. When Feng Yuxiang was appointed as the Northwest Frontier Oversight Office in January 1925, he expanded the First Army of the National Army into the “Northwest Frontier Defense Forces of the Republic of China,” or Northwest Army. 1