AIM: To investigate the effect of low-concentration intermittent oxygen inhalation on diabetic rats' hemorheology and retinal leakage. METHODS: Healthy and clean male SD rats were randomly divided into three groups: control group, diabetes group, diabetes treated with oxygen inhalation group. The rats in the diabetesgroup and the diabetes treated with oxygen inhalation group were intraperitoneally injected streptozotocin (STZ). The rats in the control group were intraperitoneally injected citrate buffer. The rats in the diabetes treated with oxygen inhalation group inhaled 300mL/L oxygen for 2 hours daily. Two months after modeling, the rats' hemorheological parameters were measured with blood rheometer. The rats' retinal Evans leakage was quantitatively measured and the integrity of the blood ocular barrier was analyzed using Evans blue as a tracer.RESULTS: The high shear viscosity of whole blood, middle shear viscosity of whole blood, low-shear viscosity of whole blood, relative index of high shear, relative index of low shear, high-shear reduced viscosity, low shear reduced viscosity, haematocrit, erythrocyte aggregation index, plasma viscosity, Casson viscosity and K value of erythrocyte sedimentation rate equation of diabetes group were higher than those of control group and diabetes treated with oxygen inhalation group. The differences among three groups were statistically significant (all P<0.05). The plasma viscosity and the Casson viscosity of diabetes treated with oxygen inhalation group were similar to those of control group. The differences were not statistically significant (both P>0.05). The high shear viscosity of whole blood, middle shear viscosity of whole blood, low-shear viscosity of whole blood, relative index of high shear, relative index of low shear, high-shear reduced viscosity, low shear reduced viscosity, haematocrit, erythrocyte aggregation index and erythrocyte rigidity index of diabetes treated with oxygen inhalation group were lower than those of control group and diabetes group. The differences among three groups were statistically significant (all P<0.05).The retinal Evans leakage of diabetes group was higher than that of control group and diabetes treated with oxygen inhalation group. The retinal Evans leakage of diabetes treated with oxygen inhalation group was higher than that of control group, while was lower than that of diabetes group. The differences among three groups were statistically significant (P<0.05).CONCLUSION: Low-concentration intermittent oxygen inhalation can reduce diabetic rats' blood viscosity, increase diabeticrats' retinal blood supply and oxygen supply, and reduce diabetic rats' retinal leakage.