Objective:To assess the TWIST1 promoter methylation state in urine sediments and evaluate their value in diagnosis of bladder cancer. Methods: Fifty patients with bladder cancer,13 patients with non tumorous urinary disease and 7 healthy volunteers were recruited in the study. The TWIST1 promoter methylation state in urine sediments was determined by real-time fluorescent quantitative PCR. The urine exfoliative cytologic examination was also performed. Results: The positive rate of TWIST1 promoter methylation was 64.0%(32/50) in exfoliated urothelial cells of 50 patients with bladder cancer, no one showed positive TWIST1 promoter methylation in the control group. The difference in the positive rate of TWIST1 promoter methylation between two groups was significant(P < 0.01). TWIST1 promoter methylation status did not correlate with stage and grade of bladder cancer,though there was a trend that more frequent methylation was detected in higher stage bladder cancer. The sensitivity of detecting TWIST1 promoter methylation by real-time fluorescent quantitative PCR in the diagnosis of bladder cancer was 64.0%,and specificity was 100%. The positive rate of urine exfoliative cytology was 48.0%(24/50),and sensitivity and specificity were 48.0% and 100.0% respectively. Conclusion: It has high sensitivity and specificity to detect the TWIST1 promoter methylation in exfoliated urothe1ial cells for the diagnosis of bladder cancer. The TWIST1 promoter methylation might be a potential biomarker for the noninvasive and painless detection method in early diagnosis of bladder cancer.