There are many third generation cephalosporins, it includes ceftriaxone, ceftazidime, cefoperazone, ceftizoxime, cefotaxime sodium, cefmenoxime, cefixime, cefdinir, cefdizime, cefadroxil, cefadroxil, cefbutene, cefminox, and laxative cephalosporin, etc., about 20 kinds. At present, the most commonly used three generations of cephalosporins in clinical practice are ceftazidime, cefoperazone, cefdinir and ceftriaxone. The antibacterial spectrum of the three generations of cephalosporins is relatively broad, and they have obvious antibacterial activity for most Gram-negative bacteria, and also have bactericidal effect on some Gram-positive bacteria. At present, the effect on Gram-negative bacteria is significantly stronger than that of first- and second-generation cephalosporins, especially for Pseudomonas aeruginosa and anaerobic bacteria, which also have different degrees of antibacterial effects and are mainly used clinically for serious infections.