Abstract: Oncogene RAS is related to many intracellular pathways that control physiological processes such as proliferation and differentiation. RAS is prone to mutate in tumor cells, among which KRAS, NRAS, and HRAS are the most common mutated subtypes. SOS1 (Son of sevenless 1) acts as a guanine nucleotide exchange factor (GEF) that activates RAS through protein-protein interactions. Therefore, it is considered that inhibitors of SOS1 could be used for the treatment of RAS-driven cancers. This article reviews advances in research on the role of SOS1 in tumorigenesis and related inhibitors, so as to provide ideas for development of the drugs targeting SOS1.