Abstract: Objective: To investigate the relationship between microvessel density (MVD), ki- 67 and bcl-6 as well as the prognosis in diffuse large B- cell lymphoma. Methods: Specific endothelial cell markers CD34 and the ki-67 and bcl-6 gene expression were detected with immunohistochemistry and microvessel density was counted by morphometry. Results: 1) There was a significant correlation-ship between the MVD and the ki- 67 labelling index but bcl- 6; 2) The microvessel count was associated with overall survival by Kaplan-Meier analysis. An average blood vessel count of less than 21.5 suggested a better survival, but a higher vessel count of more than 21.5 showed a trend to worsen the overall survival; 3) A ki- 67 labelling index of less than 59.4 suggested a better survival, but a higher ki- 67 labelling index of more than 59.4 showed a trend to worsen the overall survival; 4) A bcl- 6 positive of more than 42.0 suggested a better survival, but a lower bcl- 6 positive of less than 42.0 showed a trend to worsen the overall survival. Conclusion: The results suggest a significant correlationship among MVD, ki- 67 labelling index, bcl- 6 positive and prognosis. Moreover MVD, ki- 67 and bcl- 6 may be the useful prognostic indicators in diffuse large B- cell lymphoma.