Abstract: Objective To explore the effects of Notch3 on apoptosis, cell clone formation and migration ability in human hepatocellular carcinoma cell line HCC-LM3. Methods Notch3 expression was detected by qRT-PCR in liver cancer cell line. Expression of Notch3 was downregulated by using small RNA interference technology in cell line HCC-LM3 and apoptosis was detected by Annexin V-FITC/PI double marking flow cytometry, while clone formation assay and transwell experiment were performed to detect cell clone forming and cell migration respectively in HCC-LM3. Results Interference of Notch3 expression in HCC-LM3 can promote HCC-LM3 cell apoptosis, inhibit cell clone formation and cell migration. Conclusions Over-expression of Notch3 may be related to tumor malignant transformation .