It inhibits bacterial cell wall synthesis and has good antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, various groups of streptococci, pneumococci, some Escherichia coli, Klebsiella, Proteus mirabilis and influenza bacilli. It also has good antibacterial effect on penicillin-resistant Staphylococcus aureus.

Amoxicillin is a penicillin antibiotic that has good antibacterial activity against Streptococcus such as Streptococcus pneumoniae and hemolytic Streptococcus, aerobic Gram-positive cocci such as non-penicillinase-producing Staphylococci and Enterococcus faecalis, aerobic Gram-negative bacteria such as Escherichia coli, Proteus mirabilis, Salmonella, Haemophilus influenzae, Neisseria gonorrhoeae, and Helicobacter pylori. Amoxicillin exerts its bactericidal effect by inhibiting the synthesis of bacterial cell walls, which can quickly dissolve and rupture bacteria into spherical bodies.