Abstract: Objective: To monitor the distribution and drug resistance of clinically isolated common gram-negative bacilli so as to provide basis for appropriate use of antibiotics in clinic.Methods: The bacillus samples collected in the period of 2007 to 2009 were isolated and cultured according to the National Clinical Laboratory Procedures.The identification and drug susceptibility tests were carried out by using Micro Scan-40S semi-automatic microbiological assay and drug susceptibility system,and part of the strains was detected by K-B method.The results were evaluated in accordance with the standard of Clinical Laboratory Information Systems.Results: Eight hundred and fifty-five gram-negative bacilli were isolated.Escherichia coli,Pseudomonas aeruginosa and Acinetobacter baumann occupied the top three places.The detection rates of Escherichia coli and Klebsieua pneumoniae producing extended spectrum β lactamases were 58.6% and 29.7%,respectively;non-fermenting bacteria mainly consisted of Pseudomona aeruginosa,Acinetobacter Baumannii and Strenotrophomonas maltophilia;the sensitive rate of Escherichia coli,Klebsieua pneumoniae and Entrobacter to imipenem were all above 90.0%;the sensitive rate of Pseudomona aeruginosa to imipenem and amikacin was 62.4%,and to cefepime 43.5%;the sensitive rates of Acinetobacter Baumannii to imipenem,amikacin and luomefloxacia were 92.7%,63.4% and 60.2%,respectively;and the sensitive rate of Strenotrophomonas maltophilia to sulfamethoxazole was 100.0%.Conclusions: Clinicians should keep contact with the microbiology laboratory,be alert of the appearance of multi-resistant bacteria and use antibiotics individually and reasonably according to the drug sensitivity results so that the treatment effect could be improved and the emergence of resistant strains reduced.