The recent discovery of plasmid derived beta-lactamase production by N. gonorrhoeae has changed the outlook of treatment of gonococcal infections and may well become the single most important factor in gonorrhoea control. Penicillinase is a beta-lactamase that splits the beta-lactam ring of penicillin hetween the C and N atoms to form penicilloic acids. We have been trying to assess the prevalence of PPNG in Korea since May 1980. We report here 7 strains of beta-lactamase producing N. gonorrhoae detected by chrornogenic cephalosporin method from Jan. 1981 to Mar. 1981 at the Joong Ku puhlic health center in Seoul. In January, I strain (l.3%); February, 2 strains (5.0%); and March, 4 strains .(6 4%) have been isolated. All restrains were confirmed by sugar feriventation test. Previously only one strain of PPNG had been reported among Korean laymen. The sudden appearance of PPNG among Korean laymen in 1981 may mean the barruer between U.S. Army enc1aves and Korean public has been broken recently and/or direct irnport of PPNG frorn abroad especially from South East Asia.