Objective To investigate the effects of sodium arsenite (NaAsO2) on p14 alternative reading frame (p14ARF), murine double minute 2 (MDM2) and p53 expressions in L-02 hepatocytes. Methods L-02 hepatocytes were cultured in medium containing (0, 5, 10, 15, 20, 25) μmol/L NaAsO2 for 48 hours. The cell morphology was evaluated by phase-contrast microscopy and cell proliferation was detected by CCK-8 assay. The apoptosis of hepatocytes was detected by annexin V/propidium iodide (annexin V-FITC/PI) double staining followed by flow cytometry. The mRNA and protein expressions of p14ARF, MDM2 and p53 were detected by real-time fluorescence quantitative PCR and Western blotting. Results Compared with the control group, the proliferation activity of L-02 hepatocytes decreased and the apoptotic rate of L-02 hepatocytes increased significantly. With the increase of NaAsO2 concentration, p14ARF mRNA and protein levels decreased gradually, while MDM2 mRNA and protein levels increased gradually. There was no significant difference in the expression of p53 mRNA, but the relative expression level of p53 protein increased gradually. Conclusion The injury of L-02 hepatocytes induced by NaAsO2 may be related to the down-regulation of p14ARF expression and the up-regulation of p53 and MDM2 expression.