The pharmacokinetics and tissue distribution of DWP20367 (1-cyclopropyl-6-fluoro-8-chloro-7-(2, 7-diazabicyclo[3,3,0]tract-4-ene-7-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid), a novel fluoroquinolone, were examined in rats and beagle dogs after a single intravenous and oral administration. Analysis of DWP20367 in plasma, tissue, and urine was determined by both HPLC and microbiological assay (bioassay). The plasma concentration-time curves of the drug in rats and beagle dogs were biexponentially declined. The terminal half-life (t$_{1}$2$eta$/) of the drug in rats was about 60.1 $pm$7.3 min (i.v.) and 61.3 $pm$ 12.4 min (p.o.) in bioassay, and 86.3 $pm$19.8 min (i.v.) and 50.9$pm$ 14.9 min (p.o.) in HPLC. In beagle dogs, half-life of the drug determined by bioassay was about 121.8$pm$6.2 min (i.v.) and 111.0$pm$7.6 min (p.o.). The volume of distribution at steady-state (Vd$_{ss}$ ) was 243.8$pm$74.1 ml/kg (bioassay) and 339.2$pm$84.3 ml/kg (HPLC) in rats, and 1587.5 $pm$536.9 ml/kg (bioassay) in beagle dogs. The total body clearance (Cl$_{t}$) of DWP20367 was 3.4 $pm$ 0.4 ml/min/kg (bioassay) and 2.4$pm$0.4 ml/min/kg (HPLC) in rats, and 12.3$pm$ 1.0 ml/min/kg (bioassay) in beagle dogs, respectively. The extent of bioavailability after oral administration was 89.1%(bioassay) and 79.9% (HPLC) in rats, and 78.7% (bioassay) in beagle dogs. Urinary recovery (24-h) assayed by bioassay was 0.7% (p.o.) and 1.2% (i.v.) in rats, and 0.8% (p.o.) and 1.0% (i.v.) in beagle dogs. In rats, 24-h fecal recovery determined by bioassay was 11.2% (p.o.) and 0.1% (i.v.). Rat and human serum protein binding ratios at 2$mu$g/ml were about 90~91%. This drug determined by bioassay was also distributed by the order of liver, kidney, lung, heart, spleen and muscle 30 min after oral administration.on.