Abstract: Objective: To analyze the expression and prognostic value of CTNNA1 in hepatocellular carcinoma(HCC), and to explore the impact of CTNNA1 on the malignant biological behavior of HCC cells. Methods: Public databases and clinical specimens were utilized to analyze the expression level of CTNNA1 in HCC and its correlation with patient prognosis. Western blotting was used to detect the expression of CTNNA1 protein in HCC cell lines including Huh7, SK-HEP1, LM3, SNU449, and MHCC-97H. Lentiviral vectors were used to overexpress the CTNNA1 gene in SNU449 cells, and short hairpin RNA(shRNA) was applied to knock down CTNNA1 in Huh7 and MHCC-97H cells. Cell counting kit-8(CCK-8) assay, plate colony formation assay, cell scratch assay, and Transwell migration and invasion assays were used to detect the proliferation, migration and invasion abilities of cells with CTNNA1 overexpression and knockdown. Results: The analysis of UALCAN and GEPIA databases, combined with clinical sample validation, indicated that compared with adjacent normal tissues, the mRNA and protein expression of CTNNA1 were upregulated in HCC cancer tissues, which was associated with poor patient prognosis(P<0.05). Compared with the control group, the proliferation, migration and invasion abilities of HCC cells were significantly enhanced after CTNNA1 overexpression in SNU449 cells. Conversely, knockdown of CTNNA1 expression in Huh7 and MHCC-97H cells markedly weakened these malignant biological abilities(P<0.05). Conclusion: CTNNA1 is upregulated in HCC, and its high expression is closely correlated with poor prognosis. CTNNA1 may serve as a potential prognostic biomarker and therapeutic target for HCC.