Norfloxacin and ofloxacin both belong to quinolone antimicrobial drugs, but the difference between the two lies in the different pharmacokinetics, antibacterial spectrum, indications and so on. 1. Pharmacokinetics is different: Norfloxacin is rapidly but incompletely absorbed when taken orally on an empty stomach, which is about 30%-40% of the administered dose, therefore, the blood concentration is lower, but the concentration of the drug in urine and feces is higher. Oxyfloxacin is absorbed completely after oral administration, and the effect of food on the absorption of the drug is very little, the relative bioavailability reaches 95%-100%, and after absorption, it is widely distributed to tissues and body fluids, and the concentration in tissues often exceeds the blood concentration and reaches the effective level. 2. Different antimicrobial spectrum: Norfloxacin and ofloxacin have broad-spectrum antibacterial effect, and both have high antimicrobial activity against aerobic Gram-negative bacilli, but the antimicrobial activity of of ofloxacin is more extensive than that of norfloxacin. Ofloxacin also has good anti-microbial effect on atypical pathogens such as Pseudomonas aeruginosa, Chlamydia trachomatis, Mycoplasma, Legionella, etc., and it also has antibacterial activity on Mycobacterium tuberculosis and atypical mycobacteria, but the antibacterial activity on anaerobic bacteria is poor. 3. Different indications: Norfloxacin and Ofloxacin can be used for urinary tract infections, intestinal infections, skin and soft tissue infections caused by sensitive bacteria, while Ofloxacin can also be used for respiratory tract infections. Norfloxacin and ofloxacin are prescription drugs, if you need to use, should be standardized under the guidance of a doctor, not blindly self-medication.