Objective Ultraviolet radiation can induce the expression of matrix metalloproteinases (MMPs) in pterygium epithelial cells. To investigate the effects of curcumin on the expression of MMP 2 and MMP 9 in human pterygium fibroblasts (HPFs) on UVA-irradiation and its possible mechanism.Methods After optimizing the dose of UVA irradiation and the concentration of curcumin, HPFs in the second generation were divided into control group (no exposure to UVA, no medication), UVA group (exposure to UVA), and UVA + curcumin group (exposure to UVA + curcumin). MMP-2 and MMP-9 levels were tested by zymography. The mRNA expression of MMP-2 and MMP-9 was detected by RT-PCR. The NF-κB-DNA binding activity was detected by electrophoretic mobility shift assay (EMSA).Results Compared with the control group, the secretion of MMP-2 and MMP-9 in the UVA group was increased significantly (P<0.05), which could be suppressed by curcumin (P<0.05). The MMP-9 mRNA levels were also significantly increased in UVA group \[(100±0)% vs (247.0±10.8)%, P<0.05\], and could be inhibited by curcumin \[(88.7±5.1)% vs (247.0±10.8)%, P<0.05\]. The NF-κB-DNA binding was remarkably increased in UVA group (P<0.05), and significantly decreased after treatment with curcumin (P<0.05).Conclusion Curcumin can inhibit the expression of MMP-2 and MMP-9 in UVA-irradiated HPFs, and the mechanism involved in this protective effect might be its inhibitory effect on NF-κB activation.