Abstract: Fatty acid metabolism and the body's energy balance are closely related to tumor development. Fatty acid synthase(FASN), as a metabolic oncogene, is the core of the energy chain molecules. In recent years, many studies have found that human epidermal growth factor receptor 2(HER2) establishes a bidirectional relationship with FASN, together to promote cancer cell transformation, proliferation, invasion, metastasis and drug resistance. This paper reviews on the relationship between FASN and HER2 in tumor cells.