Liver cancer is a common malignant tumor in clinic. Studies have shown that sterol O-acyltrans-ferase 1 (SOAT1), a key enzyme in cholesterol metabolism, is closely related to the occurrence and develop-ment of liver cancer. Therefore, SOAT1 has great potential as a biomarker for the cancer. Herein, the gene encoding SOAT1 was obtained from the Huh-7 liver cancer cell line. After prokaryotic expression and pro-tein purification, the purified recombinant SOAT1 protein was used as an antigen to immunize mice. A total of 5 anti-SOAT1 monoclonal antibody cell lines, named 1F3, 1G3, 1D6, 2F8 and 4D11, respectively, were obtained by using hybridoma and other technologies. Among them, 4D11 was able to recognize the SOAT1 protein in Huh-7 cells and clinical liver cancer tissue samples. Subsequently, 4D11 was sent to a biological company for sequencing, and the amino acid sequences of the antibody variable regions were obtained. In conclusion, an anti-SOAT1 monoclonal antibody was successfully prepared by recombinant SOAT1 protein, which would not only provide the raw materials for the subsequent application of SOAT1 protein in develo-ping liver cancer companion diagnostic kits, but also lay a foundation for the establishment of SOAT1-based liver cancer diagnostic methods.