Objective To explore the effects and mechanisms of periostin overexpression on migration and invasion of nasopharyngeal carcinoma ( NPC) cell line.Methods The recombinant plasmids [ pCMV-neo ( +)-periostin ] and control plasmids [pCMV-neo (+)] were transfected into 6-10B cells using lipofectamine 2000TM reagent.The expression of periostin was detected with PCR and Western blotting .Transwell chamber invasion assay was employed to assay the migration and invasion of 6-10B cells before and after transfection .A gelatin zymogram was used to detect the activity of MMP-2 and MMP-9 in cultivated supernatant of 6-10B cells before and after transfection .The expression of integrin-αvβ5 was detected by immunohistochemistry ( IHC) in 6-10Bperiostin cells, 6-10Bvector cells and 6-10B cells as well as normal nasopharyngeal mucosa ( NNM) and NPC and at the same time periostin also was detected by immumohistochemistry in NNM and NPC, and densitometry analysis using image-pro plus 6.0 software, and the correlation between periostin and integrin-αvβ5 on NPC was assayed with statistics .Results Over expression of periostin promoted cell migration and invasion.The expression levels of integrin-αvβ5 in primary NPC and 6-10Bperiostin cells were significantly higher than those in NNM and 6-10Bvector, 6-10B cells.The expression in NPC of integrin-αvβ5 showed positively correlated with the expression of periostin (r=0.682, P<0.01).Conclusion Periostin plays an important role in regulation of cell migration and invasion probably by combining with integrin-αvβ5 to improve the activities of MMPs .