This thesis analyzes the traditional Chinese concept of Propriety (li), as it is expressed in Lao She's novel Four Generations Under One Roof . Lao She gives a clear analysis of the concept of Propriety, especially as it relates to the importance of family values. Giving both the positive and negative effects of the concept of Li, Lao She shows how family values affect people's attitudes toward their national crisis.After giving a general introduction to the concept of Propriety and its influence in Chinese history and society, the thesis describes and analyzes how the Propriety thought and its influence functions as the main theme of Lao She's long novel Four Generations under One Roof. In conclusion, the thesis demonstrates how Lao She's novel portrays the traditional Chinese concept of Propriety as the internal reason for China losing as well as for winning the war.