Mixed urinary incontinence (MUI) is a coexistence of both urgency urinary incontinence and stress urinary incontinence. Medical, Epidemiologic, and Social aspects of Aging (MESA) questionnaire is a validated and commonly used tool to diagnose predominant components of it and assess the severity, which can offer help in clinic. However, MESA questionnaire is still not available in China. The aim of the study is to translate English MESA questionnaire into a Chinese version, adapt it in Chinese culture, and validate the measurement properties among female patients with MUI and urgency-predominant MUI. MESA questionnaire will be translated and culturally adapted in China. The validation will be embedded in a multicentered randomized controlled trial targeted at women with urgency-predominant MUI. Apart from MESA questionnaire, 3 groups of patients are to receive clinical extended assessment, keep 3-day voiding diary, and complete International Consultation on Incontinence Questionnaire Short Form to evaluate the measurement properties of reliability and validity (internal consistence, test-retest reliability, construct validity, and responsiveness). If MESA questionnaire is of relatively high reliability and validity in diagnosing subtypes of MUI and assessing the severity, it can help to choose more appropriate therapy for patients and simplify the workload of clinicians. ClinicalTrials.gov NCT03803878, January 11, 2019.