ATM:To study the expression and the relationship of B-cell lymphoma/leukemia-2 (Bcl-2 )and matrix metalloproteinases-9(MMP-9) in pterygium, and to provide the theory basis for the treatment of pterygium.METHODS:The expression of Bcl-2 and MMP-9 were detected in 76 cases with pterygium by immunohistochemical method and were compared with the normal conjunctiva epithelium in other 9 cases.RESULTS:The expression of Bcl-2 and MMP-9 was higher in pterygium than in normal conjunctiva epithelium(P<0.05).The expression of Bcl-2 was related to that of MMP-9.CONCLUSION:The increase of Bcl-2 and MMP-9 are presented in pterygium, which may play an important role in the origin and development of pterygium .