Objective To study the event related potentials(P 2,N 2, P 3 latency and wave altitude) in children with atention deficit hyperactinity disorder(ADHD). Methods ADHD case group was diagnosed by employing ADHD Behavior Screen with DSM Ⅳ and Neuro psychic Examination. The normal control group was confirmed according to sex and age matched design.All the children were evoked ERP with aural oddball paradigm and the data analyzed with SAS 6.12 statistics software.Results In ADHD group, error frequency in counting target stimulant of event related potentials was higher( P