[Objective] To investigate the prevention and control effect of polysaccharide from the rhizomorph of Armillaria mellea by distilled water elution (AMP-1) on diabetic cataract in rats.[Methods] Streptozotocin (STZ),combined with freund's adjuvant (CFA),was used to induce diabetic cataract in rat,to observe the onset of lenticular turbidity by slit lamp and compare the turbid degree of eyes lens among different groups.The super oxide dismutase (SOD),glutathione peroxidase (GSH-px) and malondialdehyde (MDA) in serum and eyes lens were measured by colorimetric method.[Results] The slit lamp examination results showed that AMP-1 obviously delayed the onset of diabetic cataract and reduced turbid degree of eyes lens.Compared with model group,AMP-1 at various doses should significantly reduce the level of MDA ascended in serum of rats.Medium-and high-dose groups could increase the levels of SOD and GSH-Px in serum,and the dose of AMP-1 was closely related to the effect.[Conclusion] AMP-1 played a prominent role in prevention and treatment of diabetic cataract in rats.