Objectives To investigate the effects of sodium selenite on telomerase activity, apoptosis and expression of TERT, c-myc and p53 in rat hepatocytes. Methods Selenium at doses of 2.5, 5.0, and 10μmol/kg was given to SD rats by garage. In rat hepatocytes, telomerase activity was measured by the telomeric repeat amplification protocol (TRAP), apoptosis was detected by flow cytometry, and expressions of telomerase reverse transcriptase (TERT), c-myc and p53 were analyzed by reverse transcription-polymerase chain reaction (RT-PCR).c-Myc and P53 proteins were detected by immunochemistry. Results Selenium at doses of 2.5, 5.0, and 10μmol/kg significantly increased hepatocellular telomerase activity and induced apoptosis in a close-dependent manner. Although selenium at doses of 2.5, 5.0, and 10μmol/kg displayed no obvious enhancing effect on the TERT mRNA expression in rat hepatocytes (P>0.05), it significantly increased the c-myc mRNA and p53 mRNA expression at the dose of 10μmol/kg (p