Objective To investigate the antibiotic resistance and their genetic homology of stenotrophomonas maltophilia isolated from January 2005 to February 2006 at intensive care unit（ICU） of 6 hospitals in Bejing area.Methods The minimal inhibitory concentration（MIC） of 12 antibiotics against 82 strenotrophomonas maltophilia was determined by broth dilution method.PFGE was used to analyze the homology of 82 stenotrophomonas maltophilia.Results The drug sensitivity tests in vitro showed these strains were resistance to commonly-used antibiotics.Antibiotics with sensitive rate over 50% included Doxycycline, gatifloxacin,cefoperazone-sulbactam,levofloxacin,Compound sulfamethoxazole,Ceftazidime and ticarcillin- clavulanate. 7-18 DNA bands of different size were present in the gel and different homology was shown among the 82 strains.Four couples with homology over 85% were isolated from the same ICU.Three strain were same clones in PLA General Hospitals first hospital.2 couples from the different wards had homology of 80.6% and 79.6% of，respictively.Others strains had either poor or no homology.Conclusions No clonal outbreak is certified at ICU of 6 hospitals in Beijing area. There are only vertical dissemination of single clone in 6 ICU wards.PFGE is an effective approach for drug resistance test and epidemic analysis.