Abstract: OBJECTIV To investigate the actual situation and changing trend of nosocomial infections in a third grade hospital, and analyze the prevalence rate of nosocomial infections from 2014 to 2016, so as to provide basis for effective prevention and control of nosocomial infections. METHODS Using across-sectional survey method of clinical investigation and case investigation, the prevalence rate of nosocomial infections, the prevalence rate of nosocomial infections in key departments of infection control, nosocomial infection sites, and pathogens distribution among all inpatients in the hospital from 2014 to 2016 were investigated. RESULTS The total prevalence rate of nosocomial infections was 4.22% from 2014 to 2016, and the top 3 departments of the total prevalence rate of key departments of infection control were: Department of Hematology, cadre ward, Department of Neurosurgery (P < 0.05). The top 3 nosocomial infection sites were lower respiratory tract, upper respiratory tract, and urinary tract, accounting for 51.22%, 15.12%, and 9.27%, respectively. The top 3 pathogenic bacteria of nosocomial infections were: Pseudomonas aeruginosa, Klebsiella pneumoniae, and Bauman Acinetobacter, accounting for 26.87%, 15.67%, and 8.21%, respectively. The composition ratio order was gram-negative bacteria > fungi > gram-positive bacteria. There was no significant difference in the inspection rate of pathogenic microorganisms of nosocomial infections in recent 3 years. CONCLUSION The current situation of nosocomial infection prevention and control should not be ignored, and prevention and control work needs to continue to force. The medical staff should strengthen the awareness of prevention of infections and pathogenic microorganisms inspection, to achieve early discovery, early diagnosis and early treatment, so as to improve the level of diagnosis and treatment of infection.