AIM :To investigate the effect of N-acetylcysteine(NAC) on the rat lens expression of aquaporin protein-1(AQP-1) during ultraviolet(UV) radiation injury·METHODS: Transparent lens of healthy clean grade SD rats were randomly divided into 3 groups,the model group was exposed with UV ray,the drug group added in 300μmol/L NAC besides the UV radiation,the control group did not take above measures.Respectively they were cultivated 3,12 and 24 hours to observe the degree of lens opacification and the lens hydration degree;Western blotting was used to observe the levels of AQP-1 expression·RESULTS:The control group had high expression of AQP-1;the model group low expression of AQP-1;compared with model group,the drug group had high expression of AQP-1.By statistical analysis,between the model group and the control group,the expression of AQP-1 had significant difference(P<0.01);between the model group and the drug group,the expression of AQP-1 also had significant difference(at 3 hours,P<0.05;while at 12,24 hours,P<0.01)·CONCLUSION: UV ray can reduce the expression of AQP-1 and lead to cataract,while NAC can protect cells from UV damage to ease cataract incidence by improving the expression of AQP-1.