Penicillin potassium for injection is suitable for various infections caused by sensitive bacteria, such as abscess, bacteremia, pneumonia and endocarditis. Penicillin is the first choice for the following infections: 1. Hemolytic streptococcus infection, such as pharyngitis, tonsillitis, scarlet fever, erysipelas, cellulitis and puerperal fever. 2. Streptococcus pneumoniae infection, such as pneumonia, otitis media, meningitis and bacteremia. 3. Staphylococcus infection without penicillinase production. 4. Anthrax. 5. Clostridium infection such as tetanus and gas gangrene. 6. Syphilis (including congenital syphilis). 7. Leptospirosis. 8. Return to fever. 9. Diphtheria. 10. Penicillin and aminoglycosides were used to treat Streptococcus viridis endocarditis. Penicillin can also be used for treatment: 1. Epidemic cerebrospinal meningitis. 2. Actinomycosis. 3. Gonorrhea. 4. Person's angina. 5. Lyme disease. 6. Pasteurella infection. 7. Rat bites heat. 8. Listeria infection. 9. Many anaerobic infections other than Bacteroides fragilis. Penicillin can be used to prevent infective endocarditis in patients with rheumatic heart disease or congenital heart disease before oral, dental, gastrointestinal or genitourinary tract surgery and operation.