ObjectiveTo understand the prevalence and risk factors of healthcareassociated infection(HAI), and provide evidence for prevention and control of HAI. MethodsA crosssectional survey was adopted, bedside survey and medical record reviewing method was combined to investigate and analyze the prevalence of HAI in a tertiary firstclass hospital in 2012-2015. ResultsA total of 4 725 hospitalized patients were surveyed，the prevalence rates in 2012-2015 were 6.00%，4.77%，3.93%，and 3.05% respectively, difference was significant（P＜0.05）； antimicrobial usage rates were 30.56%，33.82%，32.84%, and 34.48% respectively, difference was not significant（P>0.05）；the main infection site was lower respiratory tract（43.00%），followed by surgical site (16.43%); the risk factors for HAI were age ≥65 years, chronic systemic diseases(diabetes, cirrhosis, chronic renal failure, chronic lung disease), immunodeficiency（white blood cell<1.5×109/L), coma, tracheotomy, and mechanical ventilation. ConclusionSurvey on HAI prevalence can promote continuous improvement of HAI management, surveillance on surgical site infection and risk factors of HAI should be strengthened.