The bacteriologic study was performed in 160 cases of the chronic suppurative otitis media who visited the department of otolaryngology, Wallace Memorial Baptist Hospital during the period of August 1992 through July 1994, and the following results were obtained. 1) Among 160 cases in which bacteria were isolated, simple infections were 126 cases(78.8%) and mixed infections were 34 cases(21.2%). 2) Among 196 isolated strains, the most frequent microorganism was Pseudomonas. And the other microorganisms were Staphylococcus, Proteus, and Providencia stuartii in decreasing order. 3) Pseudomonas was sensitive to Amikacin, Sulperazone, Piperacillin and resistant to Gentamicin, Tobramycin. 4) Staphylococcus aureus was sensitive to Vancomycin, Trimethoprim-Sulfamethoxazole and resistant to Penicilline, Tetracycline, Erythromycin, Clindamycin. 5) MRSA(Methicilline resistant Staphylococcus aureus) was 35 strains(63.6%). 6) Proteus mirabillis was sensitive to Amikacin, Sulperazone, Ceftriaxone and resistant to Kanamycin, Tetracycline, Ampicillin. 7) Providencia stuartii was sensitive to Amikacin, Cefamandole, Sulperazone, Ceftriaxone, and resistant to Kanamycin, Tetracycline.