Objective:To explore effects of transcutaneous auricular vagus nerve stimulation(taVNS)with task-oriented training(TOT)on upper extremity function and brain plasticity in post stroke hemiplegia patients. Method:Forty patients with stroke hemiplegia were randomly assigned to the experiment group(n=20)and the control group(n=20).The experiment group received taVNS combined with TOT,while the control group received only TOT.At baseline and at the end of treatment,the patients were assessed with motor evoked po-tentials(MEP),the Fugl-Meyer assessment upper extremity(FMA-UE),the Hongkong version of functional test for the hemiplegic upper extremity(FTHUE),the action research arm test(ARAT),the modified Barthel index(MBI),and the fatigue severity scale(FSS).The side effects were monitored during the treatment. Result:There were no significant differences in FMA-UE,FTHUE,ARAT,MBI and FSS between the two groups at baseline(P＞0.05).After treatment,all the functional outcomes except FSS in both two groups in-creased significantly compared with baseline(P＜0.05),and the FMA-UE、FTHUE、ARAT、MBI(occupational abili-ty)scores in the experiment group were significantly higher than those in the control group(P＜0.05).There were no significant differences in the latency,amplitude and induced rate of motor evoked potential(MEP)at baseline between the two groups(P＞0.05).Compare with the control group after treatment,the latency of con-tralesional MEP in the experiment group was significantly shorter than that in the control group(P＜0.05),and the induced rates of ipsilesional MEP were significantly higher(P＜0.05),but there were no significant differenc-es in contralesional amplitudes between the two groups.There was a significant correlation between the chang-es of contralesional MEP latency and the changes of FMA-UE(r=-0.705),FTHUE(r=-0.458),MBI in occu-pation(r=-0.654)in the experiment group(P＜0.05). Conclusion:taVNS combined with TOT can improve upper extremity motor function in patients with stroke hemiplegia by modulating plasticity of motor cortex.