The difference between the first, second and third generation of cephalosporins lies in the different representative drugs, different stability to β-lactamases, different antimicrobial effects, and different magnitude of nephrotoxicity, and it is recommended to use cephalosporins under the guidance of a doctor. 1. Different representative drugs: the first generation of cephalosporins includes cefotin sodium for injection, cefradine for injection, cefazolin sodium for injection and so on. The second generation cephalosporins include cefotiam hydrochloride for injection, cefuroxime capsules, cefaclor dispersible tablets and so on. Third-generation cephalosporins include cefoperazone sodium for injection, ceftriaxone sodium for injection, ceftazidime for injection and so on. 2. The stability of β-lactamase is different: the first, second and third generation of cephalosporins for β-lactamase stability is gradually increased, so the third generation of cephalosporin antibiotics compared to the first and second generation of β-lactamase stability is stronger. 3. Different antibacterial spectrum: the first generation of cephalosporins is mainly for Gram-positive bacteria effect is more obvious, the second and third generation of cephalosporins on Gram-positive bacteria is gradually weakening the role of Gram-negative bacteria to enhance the role of Gram-negative bacteria, and the third generation of cephalosporins on the effectiveness of Pseudomonas aeruginosa. 4. The size of nephrotoxicity is different: the first, second and third generation of cephalosporins for nephrotoxicity is gradually weakened, so the third generation of cephalosporins compared to the first generation, the second generation of cephalosporins for the nephrotoxicity of smaller.