Abstract: The research on the pathogenesis of tumor has been a hot topic in the basic field of traditional Chinese medicine. Thus, the study combined with modern medical research results based on "yang transforming into qi with yin constituting form" and fu-yang doctrine to systematically explain the mechanism of tumor formation. It is believed that the formation and development of tumor may be related to the deficiency of yang with exuberance of yin in the body due to internal and external factors. That physique is prone to produce phlegm, dampness, stasis, toxin and other pathological products, which are similar to the concepts of hyperplasia, nodules and polyps in modern medicine. At the same time, the insufficient yang transforming into qi, and the deficiency and stagnation of qi, coupled with the stagnation of yin pathogens, lead to the constraint-heat resulting in fu-yang. In the process of tumor deterioration and metastasis, yin pathogens such as phlegm, dampness, stasis, and toxin interact with fu-yang and eventually lead to the migration of tumors. Based on this, we propose a treatment on tumor that combines clearing the constraint-heat with dispersing the cold accumulations.