This book compiles nearly 500 pieces of unpublished correspondence from WANG Guowei, primarily consisting of letters sent from WANG Guowei to his son, WANG Qianming, and letters addressed to WANG Guowei from over sixty domestic and international correspondents including LIANG Qichao, HU Shi, SHEN Jianshi, GU Jiegang, LIANG Shuming, Naitō Torajirō, and others. The letters cover a wide range of content, encompassing academic discussions, social life, and personal emotions. As an important set of newly discovered historical materials, the vast information contained within these letters not only aids in advancing research on WANG Guowei and other prominent historical figures, but also serves to supplement and deepen our understanding of specific historical periods, societal conditions, and cultural contexts, possessing irreplaceable literary value.