On the eve of War of Resistance against Japanese Aggression, Japan sent personnel to Qufu several times to invite them to attend the inauguration ceremony of Confucius Temple in Japan, but they were all rejected. In the 26th year of the Republic of China (65438+February), Sun Feng, the 72nd division commander stationed in Yanzhou, ordered the couple to leave their hometown overnight. In January of the 27th year of the Republic of China, Qufu fell. A few days later, Wuhan issued an anti-Japanese declaration. Later, he moved to Chongqing, presided over the establishment of Confucius Institute, organized famous scholars, held discussions and lectures, and studied and carried forward Confucius' academic thoughts and national spirit. At that time, scholars from all over the world gathered in Chongqing, and there was a debate about old and new concepts and methods in the study of traditional culture. Kong Decheng has been hit hard. He studied under the famous scholar Wang, and his research methods were also influenced by his friends and Qu Wanli. Wu Xiangxiang, a historian, pointed out that Kong Decheng found the right direction in the academic jungle when he was weak: to be a pure scholar instead of pretending to be orthodox.

In 34 years of the Republic of China, Japan surrendered and moved to Nanjing and settled in Shanghai with the National Government. In March of the 36th year of the Republic of China, he returned to Qufu to offer sacrifices to sweep the forest temple. 1937 On March 29th, he was appointed as a representative of the National Assembly of the Republic of China. In the same year, he went to the United States to inspect culture, served as a researcher at Yale University, and was friendly with visiting scholar Luo Changpei. In March of the following year, he returned from the United States and moved to Hong Kong, Macao and Guangzhou.