Abstract: This experiment was conducted to investigate the pharmacokinetics and bioavailability of marbofloxacin in healthy dogs. A single oral or i.v. administration of the drug at the dose of 2.75 mg·kg^-1 to 8 dogs were performed in an open randomized crossover test. Blood samples were collected at different intervals after administration and concentrations of marbofloxacin were determined by HPLC method. The concentrationtime date were analyzed with 3P97 computer program to get the pharmacokinetics parameters.The drug concentration-time data were fitted to a no absorbed two-compartment open model after i.v. administration in pigs. The main pharmacokinetic parameters were as follows T1/2α(0.34±0.14)h，T1/2β (7.74±1.70)h，V(1.03±0.60)L·kg^-1， CL(0.22±0.08)L·h^-1； AUC(14.05±4.25)mg·mL^-1·h. The drug concentration-time data were fitted to a two-compartment model with first order absorption after single oral administration in dogs. The main pharmacokinectic parameters were as follows: T1/2α（(2.82±1.86)h， T1/2β（16.03±9.27）h， V/F(2.25±0.34)L·kg^-1，CL/F（0.21±0.05）L·h^-1，Tmax(1.55±0.62)h，Cmax（0.89±0.21）μg·mL^-1，AUC（13.66±2.77）mg·mL^-1·h. Marbofloxacin was rapidly absorbed and the drug was completely absorbed after single oral administration and have a good bioavailability in dogs.