[Abstract] Objective: To explore the mRNA molecular targets for diagnosis of hepatic carcionoma and to investigate their functional roles in proliferation and cell cycle of hepatic cancer cells. Methods: Based on the statistical analysis of miRNA expression data from 377 hepatic carcionoma samples and 37 adjacent non-cancerous samples in TCGAdatabase, a group of 33 differentially expressed miRNAs were identified.A further screen of these differentially expressed miRNAs was performed using the receiver operating characteristic curve (ROC curve) and Kaplan-Meier survival analysis; and with referring to the current publications, miR-451 was screened as the study subject. HepG2 cells were transfected with pLVX-shRNA2-miR-451 to over-express miR-451. The effect of miR-451 over-expression on the proliferation of HepG2 cell was determined by CCK-8 assay; while the effect on cell cycles was detected by flow cytometry. Results: The expression of miR-451 in the adjacent non-cancerous tissues was significantly lower than that in cancer tissues ([473.40±390.24] vs [1 990.47±2 118.04], P<0.05). MiR-451 could be used as an early diagnostic biomarker of hepatic carcionoma, with a high ROC value of 0.91 (sensitivity 0.89, specificity 0.87). The results of in vitro experiments showed that the proliferation of HepG2 cells was significantly decreased after miR-451 over-expression (48 h: [0.69±0.04] vs [1.08±0.05]; 72 h: [0.76±0.07] vs [1.52± 0.02]; all P<0.01), and a large number of cells were blocked in S phase(P<0.05). Conclusion: miR-451 has the potential to be used as a biomarker for hepatic carcionoma diagnosis and prognosis; moreover, it also exhibits the inhibitory effect on proliferation of hepatic cancer cells.