Korean War justified the North and the South killing each other, considering the other as enemy due to the conflicting national ideologies. On account of its cruelty, Korean War resulted in dividing the family, and caused serious torments and poverty to Korean people, forcing them to face the limit situation of living. Korean War stories descried this national tragedy plainly and bluntly. This study selected nine stories which depicts family disorganization in particular among various themes, and investigated the meaning of familism revealed in those stories. The aspects of family disorganization in those texts can be summarized as these: the disorganization between husband and wife, between parents and children, and between brothers. The ideologies causing family disorganization in those stories are egoism and nationalism. These ideologies affected the traditional familism considerably, but could not break it up completely. Egoism, which is different from individualism, dismantles social relations and pursues selfish purposes only. On the other hand, nationalism functions not on the voluntary consensus but on the national enforcement and the agitation. As the result, egoism and nationalism changed the traditional familism based on a hierarchical communication system into a horizontal and equal one. If the result of this study is applied to the study of familism described in the post-Korean War novels, it will contribute to illuminate the relationship among familism, individualism, and nationalism more completely in the modem age of Korea.