Abstract: The occurrence and development of tumor are closely related to the tumor microenvironment. The new strategy of treating malignant tumor is to interfere with the microenvironment to stop canceration. Professor Zhou， through years of clinical practices， have put forward the theory that cancerous toxin is the key to the occurring and developing of cancer. This research aims to discover the scientific connotation of cancerous toxin theory to provide scientific basis for using the theory to guide the treating of tumor in TCM by discussing the relation between pathogenesis theory of cancerous toxin and the tumor microenvironment.