Concerta and Strattera on the Executive Function in Attention Deficit Hyperactivity Disorder (ADHD) Children

Inclusion Criteria: * Age between 6 to 16 years old. Body weight between 20 to 60 kg * Meet ADHD criteria in tne Diagnostic and Statistic Manual of Mental Disorders, fourth edition (DSM-IV) through questionaire and interview * Intelligence quotient (IQ) \>= 70 * Currently unmedicated or effectively medicated with immediately released methylphenidate (The maximum dosage no more than 60mg/d) * The patient and the parent express their will to comply with the follow up including the clinical interview and all the test * The parent or the guardian sign the written consent * Can swallow the capsule Exclusion Criteria: * Have administered immediate release methylphenidate, OROS MPH or atomoxetine, but ADHD symptoms not improved. * Bipolar I or II disorder, psychosis, or pervasive developmental disorder. * Meet the DSM-IV anxiety disorder. * Any seizure disorder (except for febrile convulsion) or electroencephalogram (EEG) abnormal associated with epilepsy, or currently taking anti-convulsion drugs. * Depression disorder, tend to commit suicide, or comorbid depression symptoms which need immediate treatment. * Tics disorder, or Tourette's syndrom（DSM-IV 307.23）, or family history of tics disorder. * Narrow-angle glaucoma * cardiovascular diseases, or any diseases may be deteriorated when the pulse or the blood pressure increased, including hypertension or those taking anti-hypertension drugs. * Diseases significantly enhance the sympathetic nervous system activity, or taking sympathomimetic drug every day. * Allergic to methylphenidate or atomoxetine, or serious allergic reaction to more than one drugs or adverse event to multiple drugs before. * Serious gastrointestinal stenosis * History of alcohol, drug or other substance abuse * Those using unprescribed potential abuse drugs in screening. * In the process of the trial, the patient need to take other psychotropic drug other than the experimental drugs, including health food with central nervous system (CNS) activity (e.g. melatonin). * Might begin any structure psychological therapy addressed for ADHD in the process of the trial * Have used other psychotropic drugs in the past 30 days, including monoamine oxidase inhibitor. * Are participating other clinical trial. * Have difficulty in following up in 8 weeks. * Relatives of the investigator. * Employee of Xi-an Jensen or Eli lilly company.