·AIM:To investigate the effect of two selective cyclooxy-genase-2(COX-2)inhibitors(nimesulide and meloxicam)on proliferation and apoptosis of human pterygium fibroblasts(HPF)in culture and search for a new method to prevent the recurrence after pterygium surgery.·METHODS:HPF was incubated with 0-200μmol/L nime-sulide and meloxicam for 24-96 hours.The MTT method was used to assay the biologic activities of the two drugs in different time and different doses.The expression of proliferating cell nuclear antigen(PCNA)in each group was detected by immunohistochemistry method.The cell cycle distribution was measured by flow cytometic analysis.·RESULTS:Administration of 50μmol/L nimesulide or 100μmol/L meloxicam for 24 hours significantly inhibited HPF proliferation in a dose-and time-dependent manner(P<0.05).After treated with the two drugs in 100μmol/L for 48 hours,there was significant sub-G1 peak.The number of HPF in G0/G1 phase increased,but in S phase decreased(P<0.05),suggesting cells were arrested in G0/G1 phase.The nime-sulide(25-200μmol/L)and meloxicam(50-200μmol/L)inhibited the expression of PCNA in HPF in a dose-depen-dent manner(P<0.05).·CONCLUSION:Two selective COX-2 inhibitors can significantly inhibit HPF proliferation and induce its apoptosis.The higher selecti on of COX-2 has the stronger inhibition on the growth of HPF.·