It was perfomed to investigate for Yersinia species from 2,841 spring waters in Seoul, from 1994 to 1998. Of them, Yersinia spp. were isolated 86 isolated (3.3%). Of 86, sixty two isolates(71.1%) were Yesinia enterocolitica, followed by Y. aldovae (11 strains), Y. pseudotuberculosis (5 strains), Y. frederiksenii (3 strains), unclassified Yersinia spp. (5 strains). Yersinia spp. were highest isolated from Nowon-Gu (22 samples asd Bukhan Mountain Park isolated(18 samples). We tested 1.186 samples for SPC and colifrom from 1996 to 1998. of these tests, the positive rate of coliform was 23.6%, SPC, 9.1%, and either coliform of SPC positive 27.1%. The positive rates of coliform and SPC were decreased 26.7%, 12.7% in 1996, 25.8%, 6.3% in 1997 and 18.1%, 7.6% in 1998 , rerspectively. Of Y. enterocolitica, 78% was resistant to ampicillin and carbenicillin. In the case of Y. aldovae, only 3 of 11 isolated were resistant to carbenicillin. Y. pseudotuberculosis were resistant to colistin. Also Y. frederiksenii to carbenicillin. There were many spring waters of Y. enterocolitical isolated from Nowon-Gu and Buk-han Mountain Park. So, it needs to clean the environment of those regions.