Abstract: Objective 　To observe the expression of Cyclooxygenase-2 (COX-2) and COX-2mRNA in human meningioma and to explore the relation between the COX-2 expression and the pathology classification of meningioma. Methods 　The expression of COX-2 was detected in 64 cases of meningioma and brain tissue by immunohistochemist ry method, and the expression of COX-2mRNA was examined by in situ hybridization. Of the 64 cases, 21 cases were from human malignant meningioma, 35 cases were from the benign meningioma and 8 cases were normal cont rols. Results 　The expressions of COX-2 and COX-2mRNA in meningioma were 53. 57 % and 58. 93 %, respectively ; there is no expression in normalcontrols. The expressions of COX-2 and COX-2mRNA in malignant meningioma were significantly higher than in benign meningioma ( P < 0. 01) . Conclusion 　The COX-2 and COX22mRNA expression was high in meningioma and significantly correlated with the pathologic classification of meningioma. COX-2 gene may play a important role in prompting the angiogenesis which cont ribute to the tumor genesis and progression in meningioma.