Objective:To compare the expression of Epstein-Barr virus encoded LMP1 and E-cadherin/b-catenin in primary and metastatic nasopharyngeal carcinoma (NPC) for thepurpose of understanding their relationship. Methods:Twenty-two pairs of biopsies taken from the nasopharynx and cervical lymph node(s) of the same patient withnasopharyngeal carcinoma were collected. The expression of LMP1, E-cadherin and b-catenin was observed onimmunostained slides using LSAB method. Results:The expression rate of LMP1 in the 22 metastatic tumors(86.36%, 19/22) was significantly higher than that in the 22 primary growths (68.18%, 15/22), P<0.05. The meanexpression percentages of E-cadherin and b-catenin inmetastatic tumors (50.11%22.53% and 66.3621.05%respectively) were significantly lower than those in primary growths (71.5224.34 % and 79.40%15.05%, respectivelyP<0.05. There was a positive correlation between theexpressions of E-cadherin and b-catenin either in primary growths or metastatic tumors. Conclusion: The LMP1 imore likely to be expressed in metastatic neoplastic cells of NPC than in primary carcinoma cells, and on the contrary the expression of E-cadherin/b-catenin in metastatic cells was decreased. Accordingly, the LMP1 might have theability to downregulate the expression of E-cadherin/bcatenin, resulting in enhancement of the invasive capacity of metastatic NPC cells. Objective: To compare the expression of Epstein-Barr virus encoded LMP1 and E-cadherin / b-catenin in primary and metastatic nasopharyngeal carcinoma (NPC) for thepurpose of understanding their relationship. Methods: Twenty-two pairs of biopsies taken from the nasopharynx and The expression of LMP1, E-cadherin and b-catenin was observed on immunostained slides using the LSAB method. Results: The expression rate of LMP1 in the 22 metastatic tumors (86.36% , 19/22) was significantly higher than that of the 22 primary growths (68.18%, 15/22), P <0.05. The meanexpression percentages of E-cadherin and b-catenin inmetastatic tumors (50.11% 22.53% and 66.3621.05 % were respectively lower than those in primary growths (71.5224.34% and 79.40% 15.05%, respectively P <0.05. There was a positive correlation between theexpressions of E-cadherin and b-catenin either in primary growths or metastatic tumors. Conclu sion: The LMP1 imore likely to be expressed in metastatic neoplastic cells of NPC than in primary carcinoma cells, and on the contrary the expression of E-cadherin / b-catenin in metastatic cells was decreased. the expression of E-cadherin / bcatenin, resulting in enhancement of the invasive capacity of metastatic NPC cells.