The author used to focus his studies on politics and political culture of the Han dynasty and has made great achievements therein. In recent years, the author shifted his interest into the palace security systems of the Han, Wei, and Jin dynasties, a topic that few historians have pursued. He has spent several years poring over relevant historical materials, including the latest archaeological findings, and conducted an in-depth examination of palace security decrees and regulations. Building on previous research findings, the author succeeded to provide some new insights. His articles on this subject have been published in Historical Research, Journal of Chinese Historical Studies, Bulletin of the Institute of History and Philology and other journals, which received wide attention and positive response from the academic circle. His research has greatly advanced the understanding of the palace security systems of the Han, Wei, and Jin dynasties.