OBJECTIVE To investigate ?-lactamases genes in multi-resistant Pseudomonas aeruginosa in Guangzhou. METHODS We collected 22 P.aeruginosa strains from hospitalized patients,and detected eleven types of ?-lactamases associated genes by PCR. RESULTS CARB,IMP,TEM,VEB and VIM showed positive amplifications with positive proportions were 100.0%,95.5%,77.3%,13.6% and 4.5%,respectively.Other genes such as GIM,SPM,GES,PER,DHA,OXA-10 and SHV showed negative results. CONCLUSIONS The genes CARB and IMP have high positive rate.Different types of ?-lactamases associated genes in P.aeruginosa aften lead to multi-resistance to antibiotics,which bring great difficulties to clinical therapy and hospital infection monitoring.