Abstract: Objective : Epstein-Barr virus (EBV) is a DNA virus related to some human malignancies. The aim of thisstudy was to investigate the association of EBV infection with malignant lymphomas of different type or in dif-ferent anatomical sites. Methods : We analyzed 127 tissue samples of malignant lymphomas including 60 lym-phomas in the nasal cavity and nasopharynx, 30 lymphomas in the stomach and 37 lymphomas in superficiallymphnodes. There were 19 cases of Hodgkin's disease (HD) and 108 cases of non-Hodgkin's lymphoma(NHL). According to immunohistochemical features, all of the 108 non-Hodgkin's lymphomas were divided intothree immunophenotypes: B-cell lymphoma, T-cell lymphoma, and NK/T-cell lymphoma based on their differ-ent immune markers of CD20, CD79a, CD45RO, CD3 and CD56. In situ hybridization was employed to detectthe EBV-encoded small RNA (EBER) in tumor cells. Results : There were 46 EBER positive cases in all of the108 cases of NHL. The positive rate of EBER in NHL cases was 42.6%. The positive rate of NHL in the nasalcavity and nasopharynx was 58.3% (35/60 cases). There were 29 cases of NK/T-cell lymphoma, 19 of whichwere EBER positive. The EBER-positive rate in NK/T-cell lymphomas was 65.5% (19/29 cases). There were31 cases of B-cell lymphoma, including 16 EBER positive cases. The EBER-positive rate of B-cell lymphomain the nasal cavity and nasopharynx was 51.6% (16/31 cases). The EBER-positive rate of primary gastric NHLwas 30% (9/30 cases). There were 28 cases of gastric B-cell lymphomas, including 9 EBER positive cases.The EBER positive rate of gastric B-cell lymphomas was 32.1% (9/28 cases). There were 2 cases of gastric T-cell lymphoma, which were EBER negative. The EBER positive rate of NHL in superficial lymph nodes was11.1% (2/18 cases), including one EBER positive case in 8 cases of T-cell lymphomas and one EBER positivecase in 10 cases of B-cell lymphomas. The EBER positive rate in HD of superficial lymph nodes was 26.3%(5/19 cases). EBV infection rate was a little higher in patients with NHL (42.6%) than in patients with HD(26.3%), but with no significant difference (P>0.05). The EBER positive rate in NHL of the nasal cavity and na-sopharynx was higher than in NHL of the stomach and superficial lymp hnodes (P<0.05). Conclusion : Differenttypes of human lymphomas are strongly associated with EBV infection. The EBV positive rate is related withthe site of lymphoma.