Identification of human melanoma antigens by various molecular biological and immunological techniques and evaluation of tumor reactive T cells in patients with the identified tumor antigen and HLA tetramer technology, not only provided us more profound understanding of anti-tumor immune responses in human, but also led to reveal basic problems in each step towards immunological tumor rejection, including systemic suppressive mechanisms such as regulatory T cell induction and local inhibitory environment in tumors. Based on these results obtained from the basic and clinical researches, various improvements have been applied for immunotherapy, including active immunization with modified antigenic peptides and recombinant virus, T cell adoptive transfer with lymphodepletive pretreatment, and administration of anti-CTLA-4 Ab, although further improvement is necessary. The translational research performed on melanoma, would facilitate development of immunotherapy for other cancers.