ObjectiveTo realize the prevalence and antimicrobial use of nosocomial infection (NI) and communityacquired infection (CAI) in hospitalized patients .MethodsCrosssectional investigation on infection in patients who admitted in a hospital on October 29, 2008 were surveyed through bedside examination and medical records checkup.ResultsA total of 2 413 patients were investigated, NI prevalence rate was 4.06% (98 cases), NI case prevalence rate was 4.52% (109 cases); the prevalence rate of CAI was 23.79% (574 cases), CAI case prevalence rate was 25.24% (609 cases). The main infection sites of both NI and CAI was respiratory tract, which was 45.87% and 31.53% respectively. The main  bacteria in NI were Staphylococcus aureus (20.00%) and Acinetobacter (10.00%); The main bacteria causing CAI were coagulase negative Staphylococcus (15.38%) and Staphylococcus aureus (13.85%). Antimicrobial application rate was 39.33%, antimicrobial application rate in internal medicine department was 28.66% (364/ 1 270), which was significantly lower than that of surgical department (51.18%, 585/1 143) (χ2=127.85, P<0.01); the culturing rate of pathogens in patients with curative use of antimicrobial agents was 23.46% (137/548) in surgical department, and 36.88% (97/263) in internal medicine department, which was significantly higher than that of surgical department (12.46% ,40/321) (χ2=48.01,P<0.01).ConclusionCommunityacquired infection in this hospital is high, surveillance of high risk sites for infection should be intensified, and antimicrobial use should be standarded, so as to control the occurrence of infection.