Abstract: Based on the development process, main contents and results of green activities by the Communist Youth League (CYL) in Beijing Forestry University (BJU), this article innovatively proposed the brand vitality model of green activities, and analyzed the reasons that green activities by the CYL in BJU have such a strong vitality with 3 dimensions of the guiding force, continuing innovation and spatial expansion. The guiding force is so strong because it fits the requirements of national development with relying on the characteristics of professions and the advantages of subjects in BJU. The continuing innovation is so strong because the contents of our activities are innovated continuously, and also we actively seek the supports from all parties to strength its continuation. The spatial expansion is so strong because endogenous force is the base of strong vitality of green activities, meanwhile the spatial influence of the activities and the population of doing the activities are expanding continuously.