Objective To investigate the mechanisms of early sensorineural hearing loss of diabetic rats. Methods The diabetic model for rats was established. Every rat was checked with ABR and DPOAE before and af-ter treatment . After 14 days , the blood glucose, blood fat, SOD, GSH-Px and MDA were measured. Results For the model group, the rats" blood glucose and fat increased while the GSH-Px was reduced more than the con-trol group. The response amplitudes of DPOAE decreased at 4 000 Hz and 8 000 Hz(P<0. 05). Conclusion The damage to the hair cells caused by the affected metabolism is considered as the culprit of the sensorineural hearing loss and the changes of DPOAE took place earlier than that of ABR, thus becoming useful in detecting early hearing loss of the diabetic patients.