OBJECTIVE To compare the pharmacokinetics of levofloxacin (LVFX) between hypothermic animal and healthy animal by establishing hypothermic animal model. METHODS Eight healthy beagle dogs were randomly divided into control group（group 1，n=4）and model group（group 2，n=4）. Group 1 were administered a single intravenous dose of LVFX (25 mg·kg-1) by infusion into saphenous vein. Group 2 was administered after seawater immersion for 90 min. LVFX in plasma at different sampling time was determined by HPLC, at the same time, the temperature of animal was monitored. The pharmacokinetic parameters were calculated by 3P97 software and examined by SPSS program. RESULTS The temperature of animal in group 1 before and at 24, 72 h postdose were (37.30±0.38), (37.10±0.26) and (37.18±0.17) ℃, respectively, and those in group 2 were (37.70± 1.41) ℃ at before immersion, (36.33±0.21) and (34.45±0.46) ℃ at 45, 90 min after immersion process, (30.13±1.41), (32.95±2.29), (35.30±0.59), (35.70±0.55), (36.4±0.46) and (37.30±0.38) ℃ at 1, 2, 4, 12, 24, 48 and 72 h after administration respectively. When LVFX was intravenously administered by infusion, the plasma concentration-time curve of two groups were both fit to a two-compartment model with the main pharmacokinetic parameters as follows: ρmax (30.05±1.75) and (44.56±11.63) mg·L-1, t1/2β (8.23±0.65) and (13.69±1.78) h, AUC (247.00±14.10) and (389.79±103.14) mg·h·L-1, Vc (7.47±3.13) and (7.14±2.53) L, CLS (1.20±0.15) and (1.0±0.33) L·h-1, respectively. And there were significantly different in t1/2β and AUC between group 1 and group 2（P<0.05）. CONCLUSION Hypothermia by seawater immersion has significantly effect on the pharmacokinetics of LVFX in beagle dogs. Compared with control group, t1/2β and AUC of hypothermic beagle dog were both increased significantly. style="width:400px" rows="8" cols="">