This product is a 14-membered ring macrolide antibiotic. The antibacterial spectrum is the same as that of erythromycin and roxithromycin, but it has slightly better antibacterial effects on gram-positive bacteria such as Streptococcus, pneumococcus, and staphylococcus. It also has a certain degree of induced erythromycin-resistant strains Antibacterial activity. Clarithromycin and its metabolites in the body have enhanced antibacterial effects on influenza bacilli. This product also has a certain effect on Neisseria gonorrhoeae, Listeria, Campylobacter jejuni, and has a stronger effect on Legionella pneumoniae, Mycoplasma pneumoniae, Chlamydia trachomatis, Ureaplasma urealyticum, etc. than erythromycin. It has been developed in recent years. The role is more prominent in the variety, MIC90 is about 0.008~0.12mg/L. In addition, it has certain activity against Treponema pallidum, Mycobacterium avium, Toxoplasma murine, etc., and most of them are better than other species. In addition to having a strong antibacterial effect on anaerobic cocci, the effect on Bacteroides fragilis is better than that of erythromycin. The aftereffect of this product on Staphylococcus aureus, Streptococcus pyogenes, Influenza bacillus, etc. . This drug is a macrolide antibiotic, and its mechanism is to inhibit the synthesis of protein by blocking the connection of the 50S subunit of the nucleoprotein to produce antibacterial effects. This drug has an inhibitory effect on Gram-positive bacteria such as Staphylococcus aureus, Streptococcus, pneumococcus, etc., and against some Gram-negative bacteria such as Haemophilus influenzae, Bacillus pertussis, Gonorrhea, Legionella pneumophila and some Anaerobic bacteria such as Bacteroides fragilis, peptostreptococcus, and Propionibacterium acnes also have inhibitory effects. In addition, it also has an inhibitory effect on mycoplasma. The drug is characterized in that its antibacterial activity in vitro is similar to that of erythromycin, but its antibacterial activity against some bacteria such as Staphylococcus aureus, Streptococcus, Haemophilus influenzae, etc. is stronger than that of erythromycin in vivo. There is cross-resistance with erythromycin.