Abstract: Malignant tumor incidence increases year by year, harming human health seriously. Current treatments include radiotherapy, chemotherapy and molecular targeted therapy. T cell-mediated immune cells play a key role in the body's anti-tumor effect. In the process of immune response, the participation of coordinated stimulus signals is required to activate T cells, and these signals need "immune checkpoints" to be regulated. TIM-3, as a negative regulatory molecule, expresses selectively on activated Thl cell surface and plays an important regulatory role in the development of a variety of tumors. Therefore, we review the research advances of TIM-3 in tumor immunology through TIM-3 structure, ligands, expression in tumor, mechanism of immune regulation and immunotherapy.