Objective To compare the application of ambulatory urodynamic(AUM)and conventional urodynamic(CUD)in detecting stress urinary incontinence(SUI)and detrusor overactivity(DO)in females.Methods Incontinence questionnaire short form(ICI-Q-SF),CUD and AUM were administrated on 30 female patients with the mean age of 49.4(32-63)years.The duration of symptom was 4.7 (1-9)years.The patients were divided into 3 groups of mild(n =9),moderate(n =15)and severe (n =6)according to ICI-Q-SF.Three micturition cycles were recorded during AUM.Results SUI and DO detected by AUM were 90％ and 37％,significantly more than those by CUD of 70％ and 10％(P ＜0.05).Twenty-one moderate and severe SUI patients diagnosed by ICI-Q-SF,detected by AUM and CUD simultaneously showed that abdominal leak point pressure(ALPP)and voided volume were lower,and detrusor pressure was higher recorded by AUM than those by CUD significantly(P ＜ 0.05).Conclusions SUI and DO are easier detected by AUM than by CUD.AUM is a useful additional tool in clinical practice for those patients CUD failed to explain their symptoms.