Abstract：Objective：To monitor and assess the antimicrobial resistant of bacteria in 12 hospitals of Jiangsu province during the year of 2012. Methods：A total of 48 683 non-repetitive messages on bacteria were collected. The drug susceptibilities were tested by automated microbiology system or Kirby-Bauer disk dilution method. The results were interpreted by the Criteria published by the Clinical and Laboratory Standards Institute (CLSI 2011). The data were statistically analyzed by WHONET 5.6 software. Result：Among the 8 786 strains of Staphylococcus methicillin resistant rate were 63.8%. Among the isolated 2 744 strains of Enterococcus, the drug susceptibilies of E.faecalis to all the antibiotics were higher than those of E.faecium, but the intermediate susceptibility rate for vancomycin were 7.1% in E.faecalis. Among the 155 strains of Streptococcus pneumoniae the susceptibility rate of penicillin was more than 80% according to the break point of non-meningitis, but the susceptibility rate of penicillin reduced obviously according to meningitis. In the 20 245 strains of Enterobacteriaceae, the highest susceptibility rate was shown in carbapenems in which imipenems exhibited susceptibility rate of 93.2%, and the other 2 antibiotics with susceptibility rates of over 70% were amikacin(82.5%) and piperacillin/tazobactam (76.3%). In non-ferment bacterium, 5 658 strains of Acinetobacter baumannii showed drug-resistant rate of 67.9% to imipenems, 72.5% to meropenem, and more than 60% to other 11 examined antibiotics. The drug-resistant rate of 6 393 strains of Pseudomons aeruginosa was obviously lower than that of Acinetobacter baumannii. The strains of H.influenzae isolated from 156 patients showed the susceptibility rate of 100% to azithromycin and over 75% to piperacillin/tazobactam, cefotaxime and levofloxacin. Conclusion：The detectable rate of methicillin-resistant Staphylococcus still was the highest of gram-positive cocci. The rise of isolation rate of E.faecium may predict more difficult treatment for infection caused by enterococcus. Carbapenems kept very high antibacterial activity against Enterobacteriaceae, but the susceptibility rate was reducing. In non-ferment bacterium, the resistance of Acinetobacter baumannii to carbapenems increased at the fastest rate. The resistance rate of Pseudomons aeruginosa to carbapenems exceeded that of the third or fourth generation cephalosporin.