Abstract： Objective To retrospectively analyze the bladder function of to extraordinary daytime urinary frequency (EDUF) in children by urodynamic system and to evaluate the efficacy of bladder training.Methods A total of 204 children (126 boys,78 girls,aged 3-14 years) with a diagnosis of EDUF were recruited.The duration of symptoms was from 2 weeks to 12 years.The major symptom was frequent daytime voiding disappearing during sleeps.There was no history of urinary tract infection,urological anatomic or neurological abnormality.According to the criteria of International Children's Continence Society (ICCS),CBC (cystometry bladder capacity) and detrusor function were elevated respectively by urodynamic system.Bladder training was conducted after cystometric study.One week later,voiding frequency and urinary volume were followed up.For those with improved symptoms,one more session of training was provided.Results The 3-7 years old patients had the highest incidence of EDUF at 69.12％ (141/204).With increasing age,the incidence declined.And 57 cases (27.94％) had possible psychosocial problems or recent emotional stressors.Bladder dysfunction was found in 113 cases (55.39％) including 69 boys (54.76％) and 44 girls (56.41％).CBC decreased in 71 cases (34.8％) and detrusor instability was found in 69 cases (33.82％).One week after training,146 cases (71.57％) were cured,37 (17.14％) improved and 21 (10.29％) were ineffective.Efficacy and decreasing CBC relationship analysis revealed that the training outcome was worse in children with decreasing CBC.And 23 patients with improved symptom received the second training and 19 cases (82.61 ％) were finally cured.The total cure rate of training was 80.88％ without any complication,such as urinary retention or infection.Conclusions Cystometry urodynamic may evaluate bladder function and offer bladder training simultaneously.And it is efficacious in the treatment of EDUF in childhood.