ObjectiveTo investigate the prevalence rates of healthcareassociated infection (HAI) and antimicrobial use in a hospital in 2011-2013, and provide scientific basis for prevention and control of HAI.MethodsHAI prevalence rates and antimicrobial use in a hospital in 2011-2013 were investigated by combination of bedside visiting and medical records reviewing.ResultsA total of 3 011 patients were investigated during three years, the prevalence rates were 3.49%, 2.87% and 3.98% respectively, difference of prevalence rates during three years were not significantly different (χ2=2.105，P=0.356). Among  HAI sites, lower respiratory tract ranked first, the major pathogens were gramnegative bacilli, constituent ratios of different pathogens were not significantly different among three years（χ2=1.003，P=0.972）；antimicrobial usage rates and specimen detection rates among 3 years were both significantly different(χ2=12.569，P＜0.01;χ2=6.758，P＜0.01, respectively)，antimicrobial usage rate was highest in 2011(63.40%), and specimen detection rate was highest in 2012(62.14%).ConclusionPoint prevalence rate in this hospital is at average national level，antimicrobial usage rate decreased， the consciousness of  pathogenic detection gradually enhanced，clinical application management of antimicrobial agents  still needs to be strengthened continuously.