After several years of discouraging results, immunotherapy finally becomes a powerful, clinically valid and approved treatment for numerous types of cancer. Immunotherapy involves treatment approaches that work in various ways; some boost the body's immune system while others help guide and direct the immune cells to attack cancer cells specifically. In this review article, we summarize the current cancer immunotherapy strategies; immune checkpoint blockade, adoptive cellular therapy, cancer vaccines, oncolytic viruses, and the monoclonal antibodies and discuss the recent progress and future trends of the combination therapies.