·AIM:To investigate the changes of tear secretion and tear film stability in patients with chronic renal failure(CRF).METHODS:The Results of Schirmer Ⅰ tests(SⅠt),tear film break-up time(BUT)and fluorescein sodium staining on the cornea performed in 48 patients 96 eyes with CRF were compared with those in the control group.RESULTS:Both SⅠt and BUT were significantly lower in the CRF group compared with the control group.Rate of fluorescein sodium staining on the cornea in the CRF group was significantly higher compared with that of the control group(t=-11.103,P<0.01;t=-10.807,P<0.01).CONCLUSION:The CRF patients are found with decreased tear secretion and poor tear film stability,so they are susceptible persons of dry eye.