Levofloxacin lactate is a quinolone antibiotic. Quinolone antibiotics have been developing rapidly in recent years, from the first generation of piperic acid to the second generation of quinolone antibiotics, as well as the third generation, and now the fourth generation of quinolone antibiotics have been used in the clinical application of more. Levofloxacin lactate belongs to the third generation of quinolone antibiotics, mainly for the antibacterial spectrum of Gram-negative bacteria, and also effective against some Gram-positive bacteria. Therefore, levofloxacin can be used clinically to treat infections of the biliary system, infections of the intestinal tract, infections of the urinary system, and can also be used to treat infections of the respiratory tract and lungs. It has an antibacterial spectrum against both Gram-positive and Gram-negative bacteria, so it is relatively a broad-spectrum quinolone antibiotic.