Abstract: Objective - To explore the changes of oxidative damage indicators in workers with occupational noise induced （ ）， Methods hearingloss ONHL andtoscreenpossiblebiomarkersofONHL. Atotalof288maleworkersexposedtonoisein a large machinery maintenance enterprise were selected as the research subjects using the method of judgment sampling. After ， pure tone hearing threshold test they were divided into hearing loss group and normal hearing group according to the hearing ∶ ， ， ， loss and 1 1 pairing design of type of work age length of service with 144 people in each group. The activities of total （ - ）， - （ - ）， （ - ）， superoxidedismutase T SOD copper zincsuperoxidedismutase CuZn SOD manganesesuperoxidedismutase Mn SOD - （ ） （ ） Results glutathione S transferase GST and catalase CAT in serum of workers of the two groups were measured. The ， - ， - activitiesofGST T SOD Mn SOD and CAT in workersofthe hearing lossgroup were lowerthan those in the normalhearing （ P< ） ∶ group all 0.05 . The 1 1 logistic regression analysis of paired conditions showed that there was an association between ， - ， （ P< ） ONHL and activities of GST Mn SOD and CAT in serum all 0.05 after controlling the effects of smoking and drinking. ， - ， - ThehighertheactivitiesofGST Mn SODandCAT thelowertheriskofONHL.TheactivityofCuZn SODwasnotassociated （P ）Conclusion ， - withONHL >0.05 . TheactivitiesofserumantioxidantenzymessuchasGST Mn SODandCATarerelatedto ONHL.ThoseantioxidantenzymescanbeusedaseffectivebiomarkersforONHLworkers.