This study was conducted to investigate the effect of nitidine chloride (NC) on the proliferation and apoptosis of nasopharyngeal carcinoma cell line CNE1, CNE2, TWO3, and C666-1, and to explore its antitumor mechanism.NC was dissolved in IMDM medium and cultured with nasopharyngeal carcinoma cell line CNE1, CNE2, TWO3 and C666-1. Cell morphology, cell proliferation, cell apoptosis, p53 mRNA and p53 protein levels were assessed.After incubation with NC for 24 h, typical apoptotic morphology was observed. NC inhibited the proliferation and induced apoptosis of all 4 cell lines in a time-dose dependent manner. p53 mRNA and p53 protein levels were significantly increased.NC inhibited proliferation and induced apoptosis of nasopharyngeal carcinoma cells with upregulation of p53 gene.