Abstract: Objective To explore the characteristics of evoked potentials P300 and mismatched negativity (MMN) in treatment-refractory schizophrenia.Methods 21 schizophrenia patients as case group and 26 healthy subjects as normal control group were measured events-related potential P300 and MMN,and the differences of P300 at F3,F4,Fz,Cz and MMN at Fz,Cz,Pz of the two groups were compared.Results ① The reaction time of case group [ ( 408.91 ± 202.24 ) ms ] was longer than normal control group ( ( 361.60 ± 254.32 ) ms ),and the difference was significant (P < 0.05 ).②P300 latency at F3,F4,Fz,Cz of case group ( ( 385.92 ± 53.14 ) ms,(400.31 ± 51.32) ms,(386.77 ± 62.68) ms,(374.77 ± 57.61 ) ms) were significantly longer than those of normal control group ( (341.00 ± 30.42) ms,(335.23 ± 29.71 ) ms,( 338.65 ± 30.09 ) ms,( 344.42 ± 30.86 ) ms).P300 amplitude at F4,Fz of case group( (4.68 ± 2.90) μV(5.83 ± 3.73) μV) were significantly lower than those of normal control group ( (6.71 ± 2.57 ) μV,(7.99 ± 2.78 ) μV),P < 0.05.③MMN aptitude at Fz of case group ( (2.77 ± 2.25 ) μV) was significantly lower than that of normal control group ( (5.87 ± 3.28 ) μV) (P <0.05 ).The control group presented the expected reduction in the amplitude of the MMN from frontal to central and parietal locations.MMN amplitude of case group was contrary.Conclusion Treatment-refractory schizophrenia patients have cognitive function impairment.