MDM2 gene amplification and overexpression were detected by DNA dot blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) in 32 cases of nasopharyngeal carcinoma (NPC), 10 cases of chronic inflammation of nasopharyngeal epithelium(CINE) and NPC cell line HONE1. One case of NPC showed MDM2 gene amplification, NPC cell line HONE1 and ten cases of NPC showed MDM2 mRNA overexpression. No MDM2 gene amplification and overexpression were found in CINE. MDM2 mRNA overexpression was significantly related to cervical lymph node metastasis, but not to T stage of NPC. The results indicate that MDM2 gene may play an important role in the pathogenesis and the process of metastasis of NPC.