Penicillin is applicable to hemolytic streptococcus pneumoniae, and to penicillin sensitive (not produce penicillin enzyme) aureaus etc gram-positive cocci caused by infection, also can be used in the treatment of streptococcus viridans produce and bowel aureus infective endocarditis and tetanus, gas gangrene, anthrax, diphtheria, epidemic cerebrospinal meningitis, liszt disease rat, bite hot, sypsyphilis, clap, elegant, relapsing fever, leptospirosis, courageously sen angina, actinomyces disease etc. Pharmaceutical intermediates penicillin potassium can be converted into the corresponding, 7-6 - APA ADCA, 7 - GCLE ACA and intermediates, and such made corresponding with various therapeutic effect of other antibiotics products.