Abstract: Immune checkpoints are molecules present on the surface of immune cells, and are critical in regulating immune responses. In recent years, a large number of immune checkpoints have been identified as abnormally expressed on cancer cells, and have been found to be closely associated with tumor progression. Based on those immune checkpoints, many anticancer therapies, e.g. mAbs, chimeric antigen receptor T cells (CAR-T), and antibody conjugated drug (ADC), have been developed. B7-H3, a newly discovered immune checkpoint ubiquitously expressed by cancer tissues, is capable of driving tumor proliferation, immune evasion, drug resistance and metastasis. In an effort to provide some reference for drug development, this review summarizes recent studies of B7-H3 with its effects and mechanisms.