The aim of this study was to evaluate the prevalence and associated risk factors of urinary incontinence (UI) in Chinese women. In the cross-sectional survey, 20,000 Chinese women 20 years or older were randomly selected and interviewed with modified Bristol Female Lower Urinary Tract Symptoms questionnaires to estimate population prevalence rates and identify potential risk factors. A total of 19,024 women were included in the analysis and 976 excluded; qualified rate is 95% (19,024/20,000). Of the Chinese women aged from 20 to 99 years (mean +/- SD, 45 +/- 16 y), the overall prevalence rate of UI was 30.9%. Estimates of stress urinary incontinence (SUI), urge urinary incontinence, and mixed urinary incontinence prevalence were 18.9%, 2.6%, and 9.4%, with a corresponding proportional distribution of 61%, 8%, and 31%, respectively. The prevalence of mixed urinary incontinence increased with aging, whereas the prevalence of SUI peaked in the group of women aged 50 years and that of urge urinary incontinence in the group of women aged 70 years. Only 25% of women have consulted doctors on this issue. Through multivariable logistic regression analysis, we identified age, vaginal delivery, multiparity, alcohol consumption, central obesity (women's waist circumference, >/=80 cm), constipation, chronic pelvic pain, history of respiratory disease, gynecological events, pelvic surgery, and perimenopause and postmenopause status as potential risk factors for SUI, among which age, vaginal delivery, and multiparity are three major risk factors. Our findings suggest that the prevalence of UI is high in China, with SUI as the most common subtype. Age, vaginal delivery, and others are risk factors for SUI.