The investigation department was established in 1928. When the Northern Expedition was won, the Kuomintang Central Committee moved from Guangzhou to Nanjing, so an investigation section was set up in the Central Organizing Committee (later the Central Organization Department), with Chen Lifu as the section chief. At that time, he was the secretary of the Organizing Committee, and was appointed as the section chief by Ye Xiufeng, and 1929 was appointed as the section chief by Xu Enceng. When the investigation department was established, the number of people was small, and the investigation task was aimed at the factional struggle within the party. Later, due to the need of the anti-* * situation, it became a tool of partisan struggle. Then an "agent training class" was held and many people were recruited. And set up a spy work headquarters in Zhanyuan, Xuwangfu, Daoshu Street, Nanjing, with Xu Enceng as the director, Zhang Chong as the deputy director and Pu Mengjiu as the secretary. At that time, the headquarters of this agent was secret, called "bastard". The open investigation department within the party was expanded to the investigation department, with Pu Mengjiu as the director. The secret service headquarters includes the staffing and funds of the public investigation department. There are intelligence section, training section and general affairs section under the agent headquarters, as well as guidance and action section.
The era of the secret service headquarters is the most reactionary and rampant era of the central organs, and the secret service boasts itself as the "golden age" in the history of the secret service. These old spies were promoted to higher positions in the Kuomintang. They hold an agent investigation certificate (called a "passport") and can do whatever they want anywhere, and even mobilize the military and police. The agents in the secret service headquarters not only destroyed the central organs and many local leading organs at all levels at that time, but also lured some defectors from China who were not firm in their positions. Some of them have become senior backbones of the Central Unity Organization. For example, Gu, a leader who worked for the political security of the Central Committee in Shanghai, taught the Central Committee's agents technology after his arrest and rebellion. His book "Intelligence Business" has long been used by the central organization as a textbook for training special agents.
In order to centralize and unify the command and strengthen the anti-* * spy activities, Chiang Kai-shek unified the secret service headquarters of CC Department and the secret service of Fuxing Society on 1935, and established the Intelligence Bureau of the Military Commission (also known as the "Bureau of Investigation and Statistics"), with Chen Lifu as the director and Chen Zhuo as the deputy director. The bureau consists of three divisions. Xu Enceng, the first division commander, is responsible for the inner-party investigation; Dai Li, director of the second division, is in charge of military and police investigation; The Director of the Third Division was appointed by Chen Chao, and later by Ding Mocun, who was in charge of post and telecommunications inspection. Although the form is unified, it is actually different. The secret service headquarters and secret service institutions still exist as usual, and the Intelligence Bureau of the Military Commission is actually just a reporting institution.