Objective To compare three methods for detecting extend-spectrum ?-latamases (ESBL s) and investigate current resistance of ESBL s.Methods 538 isolates of Enterobacter were detected by VITEK-AMS, compound piece type confirm test, and double-disk synergy test.Results 20.1% (108/538) was found to be ESBL s positive by VITCK-AMS. The positive rate of ceftaxime/clavulanic acid and ceftaxime compound pieces test was 19.5% (105/538). The positive rate of double-disk synergy test was 13.0%. The resistant rate of 12 antibiotics to ESBL s positive strains was significantly higher than ESBL s negative strains.Conclusions It is important to select the proper and rapid method to detect ESBL s in time.