Currently, bacterial pneumonia can be classified into community-acquired pneumonia and hospital-acquired pneumonia according to the setting in which it occurs. For community-acquired pneumonia, the most common causative organisms are mainly gram-positive bacteria, including mainly Streptococcus pneumoniae and Haemophilus influenzae, and atypical pathogens such as Mycoplasma pneumoniae, Chlamydia, and Legionella. For such bacterial infections, effective anti-infective treatment is usually carried out with penicillins as well as first-generation cephalosporins, second-generation cephalosporins and third-generation cephalosporins in ceftriaxone and cefotaxime, often in combination with azithromycin and other drugs. The other is hospital-acquired bacterial pneumonia, which is more commonly associated with Gram-negative bacterial infections, such as Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii. Cephalosporin III, Cephalosporin IV or carbapenems, such as imipenem-cistatin sodium, meropenem, etc., are usually used for effective anti-infective treatment against these bacteria.