The review presents analysis of the papers that discuss mechanisms of antitumor immunity. The role of innate and adaptive immune reactions as well as local and systemic is considered in terms of immune defense in clinical and experimental studies. The article discusses characteristics and role tumor-associated antigens for clinical practice. Various types of immune effector cells, including T-cells, NK-cell, DC, tumor associated macrophages, etc., and cytokines, are discussed regarding their contribution into antitumor immune response. The authors also refer to the hypothesis of “immunoediting” and its part in antitumor immunity.