This book contains ten important theoretical articles by Qu Qingshan, Director of the Institute of Party History and Literature of the CPC Central Committee, in the order of Party History, History of the PRC, History of the Reform and Opening-up, and History of Socialism Development. The theme of party history study is a thread through these articles, which provides a meaningful inspiration for the current "four histories (History of the CPC, the PRC, the Reform and Opening-up and Socialism Development)" propaganda. The author divides the century-long history of the CPC into four historical periods and points out the knowledge points that must be mastered for each period accordingly. The method is instructive for the exact identification of the theme, timeline, and essence of the party's development history, as well as the correct understanding and scientific evaluation of the major events, significant meetings, and important figures.