Macrolides are generally referred to as macrolide antibiotics, and currently commonly used macrolide antibiotics include azithromycin, roxithromycin, clarithromycin, etc. Azithromycin has the strongest activity against Mycoplasma pneumoniae in this class, so it is particularly widely used against mycoplasma pneumonia, especially in pediatric patients. Clarithromycin has the strongest activity against gram-positive bacteria among macrolides, and is highly stable to gastric acid and completely absorbed orally, so it is mostly used in oral form in clinical practice, mainly for upper and lower respiratory tract infections caused by Streptococcus pyogenes or other sensitive bacteria, and combined with other antibacterial drugs for Helicobacter pylori eradication treatment. These drugs can also be used for community-acquired respiratory tract infections or genitourinary tract infections caused by sensitive Mycoplasma, Chlamydia, Haemophilus influenzae, and Catamorax, etc. Other drugs can also be used for Mycobacterium avium infections in combination.