ObjectiveTo find out the major isolates distribution, drug resistance changes of multidrug-resistant organisms (MDRO) in 2013 for rational use of antibiotics and hospital infection control. MethodsA total of 32 566 cultured bacteria samples from the patients diagnosed between January 1st and December 31st 2013 were collected, using conventional tube biochemical assays and semi-automatic automicrobic (AMS) for bacteria identification; and antimicrobial susceptibility testing, major drug resistance mechanism detection were performed according to CLSI documents. MDRO definition was made according to the 2011 international consensus from European Center for Disease Control and Prevention (CDC), American CDC, Clinical and Laboratory Standards Institute (CLSI), and Food and Drug Administration. The data was analyzed by WHOnet 5.6 software. ResultsWe got 3 684 strains isolates, G- accounted for 76.08%, G+ 16.80%, fungi 7.11%, and fastidious bacteria 17.29%. The top ten isolates in order were:E.coli, A.baumannii, Ps.aeruginosa, H.influenzae, K.pneumoniae, S.aureus, S.pneumoniae, A.fumigatus, M.catarrhalis and C.freundii. From the first quarter 2012 to the fourth quarter 2013, the extended spectrum β lactamases (ESBL)-producing E.coli increased from 40.23% to 53.54%, ESBL-producing K.pneumonia increased from 14.28% to 34.78%, XDR-A.baumannii increased from 62.38% to 99.25%, metalloenzyme-producing Ps.aeruginosa increased from 7.37% to 25.37%, methicillin resistant staphylococcus aureus increased from 23.81% to 58.70%, and VRE increased from 0.00% to 28.12%. ConclusionIn the isolates, the percentage of G- was the highest, and the rate of MDRO are all unremittingly raising, which suggests us should pay more attention to microbiology analysis, rational use of antibiotics, strengthening hospital infection control, reducing the bacterial resistance, and strengthening MDRO surveillance.