Abstract: High levels of adenosine promote tumor growth by inhibiting the tumor immune response and stimulating tumor angiogenesis, plays an important role in immune escape and tumor progression. The large amount of adenosine is produced by the ecto-5'-nucleotidase CD73. Therefore, regulating adenosine levels by inhibiting the activity of CD73 may be a promising therapeutic strategy for future tumor immunotherapy. Currently, research on CD73 inhibitors is still in the early stage, and no small molecule CD73 inhibitors have been approved for marketing. This article provides a brief review of the current research status of the currently reported CD73 small molecule inhibitors in terms of their inhibitory effects and structural design, and look forward to the future research direction of CD73 small molecule inhibitors, with a view to provide more information for the development of innovative small molecule drugs targeting CD73.