Abstract: OBJECTIVE To investigate the influence of DNA methylation of vitamin D receptor on urinary tract nosocomial infection, and put forward new ideas for the prevention and control of urinary tract nosocomial infection.METHODS A total of 454 patients hospitalized in the second affiliated Hospital of Fujian Medical University from Jan. 2017 to Dec. 2018 were divided into infection group (n=186) and non-infection group (n=268). The high-resolution melting curve(HRM) was used to detect the DNA methylation level of VDR gene in peripheral blood and the Logitic multiple regression was used to analysis the influence of DNA methylation in vitamin D receptor gene to urinary tract nosocomial infection. Sex, age, length of stay and urinary intubation were analyzed. The influencing factors of urinary nosocomial infection in urological patients and the effect of VDR gene DNA methylation on urinary tract infection were summarized.RESULTS A total of 161 strains were detected in the infection group, including 119 strains of Gram-negative bacteria (73.91%), 33 strains of Gram-positive bacteria (20.50%) and 9 strains of fungi (5.59%).The top bacteria detected in the infection group were Escherichia coli, Enterococcus faecium, Klebsiella pneumonia and Pseudomonas aeruginosa. The Tm values of different bacterial were significant(P<0.05). The Tm value of Gram-negative bacteria was significantly higher than that of Gram-positive bacteria and fungi (P<0.05), but there was no significant difference between Gram-positive bacteria and fungi (P=0.407). The Tm value in infected group was significantly lower than that in the control group(P<0.001), and the degree of DNA methylation in the infected group was lower than that in the control group. After adjusting demographic factors, long hospitalization days, urinary tract intubation, and combined use of antimicrobial drugs were the risk factors for urinary tract nosocomial infection. The level of methylation of VDR gene was a protective factor for urinary tract nosocomial infection (P<0.001). CONCLUTION The high level of VDR gene DNA methylation is the protective factor of urinary tract nosocomial infection. DNA methylation plays an important role in the process of nosocomial infection.