Objective: Matrix metalloproteinases-9 (MMP-9) is a proteolytic enzyme that play an important role in cancer invasion and metastasis because of its capability to degrade or break down both extracellular matrix and basement membrane. According to recent studies, single nucleotide polymorphism (-1562C/T) in MMP-9 promoter may down regulate expression of gene MMP-9. In this study, the authors analyzed polymorph isms in the MMP-9 promoter in some nasopharyngeal carcinoma (NPC) patients, to find the association between the polymorph isms in MMP-9 promoter and the metastasis of NPC. Methods: Total genomic DNA was isolated and purified from the blood samples of 6 NPC patients and 3 healthy people. MMP-9 promoter was amplified by using a pair of primers MMP-9F and MMP-9R. The PCR products of about 442bp in length were purified and used for sequencing of the inserts in both directions. Results: 2/6 NPC patients in III &IV stages have sites -1562C/T in MMP-9 promoter. the authors found two sites -17390/ A that have been not public in any database. Conclusions: Polymorphism (-1562C/T) in MMP-9 promoter may relate to the metastasis of Vietnam NPC.