The procedure of routine bacteria-detective methode are very complicated, so are MIC methods for drug detection.The results of drug sensitive test with disk diffusion are not stable.However,the Auto Microbic System VITEK AMS has made it possible to carry out bacterial identification, drug-sensitive test and MIC detection rapidly and accurately. The results of AMS of 382 clinically isolated Gram-negative bacilli showed that the strains contianed P.aeruginosa (32.5%), K. pneumoniae(18.6%), E. coli(16.5%), A.calcoaceticus(13.1%) E.claocae(12%), E. aezogenes(4.2%), Proteus mirabilis(3.1%), and multiresist tstains were common in them. The resistant rate of the above strains to two to six antibiotics were 84.1%~100%, 67.6-100%, 59.2-99.2%, 52.1-95.9%, 40.8-89.5%, respectively. All above strains had the lowest resistance to Amikacin and the highest to Ampicllin. It is significant that clinical doctors should choose right antibiotics according to the accurate results of AMS.