Objective To evaluate the safety of cornstalk bedding material for SD rat breeding.Methods All SD rats were randomly divided into control group and cornstalk groups.The rats were killed after being raised for 6 months.The blood biochemical indexes were measured,and histopathological examination of a number of organs were performed.Results The eight blood biochemical indexes of SD rats in the two groups were all in normal range and showed no significant difference(P>0.05).No significant pathological changes were observed in the examined organs.Conclusion The cornstalk bedding material can be safely used in SD rat breeding.