Introduction: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality in the world. Therefore, more and more studies are developing novel therapies to treat this disease. The pre-clinical trials on animals are a vital step to evaluate the efficacy as well as side effects of these novel therapies. Hence, this study aimed to develop the murine model of HCC using 3 kinds of mice: NOD/SCID, nude and Balb/c mice. Methods: HCC cell line HepG2 was used in this study. They were injected into 3 kinds of mice: NOD/SCID, nude and Balb/c mice at three doses: 5 x 106, 2.5 x 106 , and 1.25 x 106 cells. Tumor size and body weight of the mice were recorded daily. To confirm these tumors in mice as malignant tumors, they were removed and analyzed by histopathology. Results: The results showed that in nude mice, the tumors appeared after 1 day of injection and could bedetected by the naked eye
they continuously developed until the end of the study. In NOD/SCID mice, the tumors could be detected by the naked eye after 3 days of injection
their sizes also increased until the end of the experimental study. Meanwhile, in Balb/c mice, although the tumors could be observed by the naked eye on the 3rd day after cell injection, they regressed and markedly disappeared after 30 days. The dose of 5 x 106 cells per mouse induced the largest tumors (1.2 cm in diameter) in NOD/SCID mice. The histopathological analysis showed that the tumors collected from nude and NOD/SCID mice also displayed the poorly differentiated malignant carcinoma with muscle tissue invasion. Conclusion: Both nude and NOD/SCID mice are appropriate for future studies to establish HCC murine models using HepG2 injection.