Abstract: The work “Some Theoretical and Practical Issues on Socialism and the Path to Socialism in Vietnam” comprises 29 outstanding articles and speeches by General Secretary Nguyen Phu Trong. The content of these articles and speeches reflects a high level of theoretical insight, discussing a wide range of theoretical issues, among which each article addresses the issue of “Great Solidarity” from various perspectives. In this paper, the author focuses on clarifying the concept of Great Solidarity from General Secretary Nguyen Phu Trong’s viewpoint and emphasizes that promoting the tradition of Great Solidarity is a decisive factor in ensuring the sustainable success of the revolutionary cause in Vietnam, while also identifying some issues for the new period. Keywords: Solidarity, great solidarity, great solidarity of the entire people, great solidarity of the entire nation