Abstract: Autophagy is a selfdigestion process， wrapping cytoplasmic proteins or organelles to form vesicles and degradation in the lysosome. Autophagy plays an important role in the maintenance of intracellular homostasis. Autophagy exists in many tumors and is involved in cell malignant transformation and tumor cell growth. In early phase of tumorigenesis， autophagy is used to clear the intracellular folding abnormal protein and dysfunctional organelles such as mitochondria. Autophagy can also inhibit cell stress response and prevent genetic damage. When tumor developes， autophagy helps tumor cells survive in nutritional deficiencies and hypoxic conditions. The study of autophagy in the occurrence and progression in tumors will provide new therapeutic strategy for tumor treatment.