From the total 116,429 clinical specimens submitted to "C" hospital from January 2005 to December 2006, 2,195 strains of streptococci were isolated. Twenty four species of Streptococcus were identified with 0.1~19.8% isolation frequencies, of which S. pneumoniae was 19.8%, S. agalactiae 16.2%, S. anginosus 9.8%, S. constellatus 5.0%, S. oralis 3.9%, S. mitis 3.3%, S. pyogenes 2.7%, S. salivarius subsp. salivarius 2.2%, S. sanguinis 1.9%. For S. pneumoniae, clinical specimens showing over 9.0% isolation rate were 82.8% in sputum, 9.2% in blood, and for Streptococcus species other than S. pneumoniae, 18.0% in sputum, 16.0% in urine and 9.7% in blood. The antimicrobial agents that showed over 90.0% susceptibility were cefotaxime, gatilfloxacin, imipenem, levofloxacin, linezolid, moxifloxacin, rifampin and sporfloxacin in S. pneumoniae, ampicillin, cefotaxime, cetriaxone, levofloxacin, linezolid, penicillin, quinupristin/dalfopristin and vancomycin in S. agalactiae, chloramphenicol, clindamycin, levofloxacin and vancomycin in S. anginosus, levofloxacin, vancomycin in S. constellatus subsp. constellatus, vancomycin in S. oralis, vancomycin in S. mitis, chloramphenicol, clindamycin, levofloxacin, quinupristin/dalfopristin and vancomycin in S. pyogenes, chloramphenicol, levofloxacin and vancomycin in S. salivarius subsp. salivarius, chloramphenicol, levofloxacin and vancomycin in S. bovis II, chloramphenicol, levofloxacin, quinupristin/dalfopristin and vancomycin in S. dysgalactiae subsp. dysgalactiae, levofloxacin, chloramphenicol and vancomycin in the whole group of 10 Streptococcus spp. other than Streptococcus pneumoniae.