New tumor antigens are continuously being discovered due to the improvement of immunologic techniques. Whether dendritic cells induce immune activation or immune inhibition after they capture tumor antigens depends on the danger signals (GM-CSF, MCP1, and HSP) or the inhibitory signals (TGF-β, IDO, and iNOS) released by tumor cells. Under the regulation of danger signals, dendritic cells activate Th1 immune response and eliminate tumors; under the regulation of inhibitory signals, they activate Th2 immune response and can not effectively eliminate tumors. Progress in tumor immunotherapy mainly is manifested by antibody-based therapy, T cell-based therapy, and tumor vaccine-based therapy. To day at least 7 antibodies have been confirmed effective when combined with chemotherapeutic agents in treatment of tumors. Despite of the progress made in antibody therapy, discovery of new targets, development of new antibodies, and expanding of the application scope to more tumors still need intensive research efforts. The clinical effects of T cell-based therapy have not been satisfactory; most tumor vaccine-based therapies are in phase Ⅰ and Ⅱ clinical trial, and the outcomes of few phase Ⅲ clinical trials are not satisfactory, leaving more work to be done for improvement. As we understand more about the roles of antibody in immune surveillance, it will help to make immunotherapy of tumors a promising strategy.