〔Abstract〕 Objective To investigate the relationship between tropomodulin 3(TMOD3) and the malignant biological characteristics of hepatocellular carcinoma, and the predictive potential of TMOD3 as a biomarker for the recurrence and metastasis of hepatocellular carcinoma. Methods Firstly, the structure of TMOD3 and its subcellular localization in cells and tissues were analyzed using database of Human Protein Atlas. Then explored the differential expression of TMOD3 in hepatocellular carcinoma tissues and normal liver tissues and its impact on clinical pathological characteristics and prognosis using TCGA and GEO datasets. Subsequently, the STRING database was utilized to explore the interacting proteins of TMOD3, followed by enrichment analysis conducted using the Metascape database. Finally, Logistic regression was used to analyze the independent risk factors for metastasis of hepatocellular carcinoma and evaluated the importance of predictive variables using ROC curves and Wald tests. Survival analysis was conducted using the Kaplan-Meier curve and the Log-rank test. Results TMOD3 was localized to actin filaments in cells, and compared with normal tissues, the expression level of TMOD3 in liver cancer tissues is higher(P<0.05), and high expression of TMOD3 was closely related to lymph node metastasis and distant metastasis of hepatocellular carcinoma patients(P<0.05). Enrichment analysis results revealed that TMOD3 and its interacting proteins mainly function and signaling pathways related to tumor invasion and migration. Logistic regression found that TMOD3 was an independent risk factor for recurrence and metastasis of hepatocellular carcinoma(OR: 4.359, 95%CI: 1.235-15.384,P=0.022). Survival analysis revealed that high expression of TMOD3 was associated with poor OS, DFS, and RFS of hepatocellular carcinoma patients(P<0.05). Both ROC analysis and Wald test indicated that TMOD3 has good predictive characteristics for recurrence and metastasis of hepatocellular carcinoma. Conclusion TMOD3 is closely associated with the invasion and metastasis of hepatocellular carcinoma and is an independent risk factor for the recurrence and metastasis of liver cancer. TMOD3 performs well in predicting the recurrence and metastasis of hepatocellular carcinoma and has the potential to become a biomarker for predicting the recurrence and metastasis of hepatocellular carcinoma.