Abstract: Carbon dots (CDs) are fluorescent carbon nanomaterials with a wide range of applications, showing excellent physical, chemical and optical properties. At present, heteroatom doping is recognized as one of the most effective methods to improve the optical properties of carbon dots. Boron doping is recognized as an effective strategy for further enhancing the optical performance of CDs, owing to the comparable atomic size and electronegativity between boron and carbon atoms, combined with boron's exceptional electron-withdrawing capability. In this paper, the research progress of boron-doped carbon dots is reviewed from three aspects: optical properties, different synthesis methods, and applications. In particular, the different synthesis methods of boron-doped carbon dots and the different ligand selections are summarized in detail. In addition, the potential applications of boron-doped CDs in optical sensors, bioimaging, and information security and anti-counterfeiting are reviewed. Finally, we propose and discuss the challenges and development prospects of boron-doped CDs.