Adhering to the concept of system,an important ideological and working method in Marxism,is promi-nently reflected in the theory and practice innovation of Xi Jinping's theory of rigor in the Party's internal po-litical activities.It should be understood from its forward-thinking,holistic planning,strategic layout,and comprehensive advancement.Specifically,this concept is manifested in several aspects:systemically guarding against internal dangers and external risks faced by the party,comprehensively examining the history,real-ity,and future of rigor in the Party's internal political activities;planning based on the comprehensive gov-ernance of the party and the overall situation of socialism with Chinese characteristics;designing the top-level framework for serious party political life;and innovating means,approaches,and methods in the Party's in-ternal political activities.Its profound understanding is beneficial to better grasp and apply the ideological and working methods of Marxism,and it has important methodological significance for further promoting the quality improvement of the Party's internal political activities in the new era.