To investigate TLR2 (Toll-like receptor 2) mRNA expression in ischemic hepatic lobes under the condition of partial hepatic ischemia/reperfusion injury in BALB/c mice and its relationship with liver function impairment. A partial ischemia/reperfusion injury model was established. The portal vein and hepatic artery supply to the median and left lobes of the liver were obstructed by an atraumatic artery micro-clip, with the obstruction lasting for about 60 min. Then reperfusion was fulfilled by removal of the clip. The liver samples were collected at the 4th h after the restoration of blood inflow. Total RNA was extracted from the liver samples and analyzed quantitatively by method of real-time PCR. At the same time, portal vein serum and plasma were taken respectively for further detection of the level of endotoxin, tumor necrosis factor alpha (TNF-alpha) and plasmic alanine aminotransferase (pALT). The results indicated that TLR2 mRNA in ischemic lobe was up-regulated markedly in mice partial liver ischemia/reperfusion injury model compared to that in sham operation group (deltaCt: 1.05 +/- 1.02 vs 5.08 +/- 1.36, P<0.001). The level of portal vein pALT and TNF-alpha increased significantly (112.32 +/- 17.56 pg/ml vs 6.07 +/- 5.33 pg/ml, P<0.01; 890 +/- 127 microm/L vs 30 +/- 5 microm/L, P<0.001) . However, the level of portal vein endotoxin remained below the normal line, suggesting a state of non-endotoxemia. TLR2 mRNA expression in ischemic lobe, as well as portal vein pALT and TNF-alpha, was up-regulated in the model of mice partial ischemia/reperfusion injury, suggesting the involvement of TLR2 in ischemia/reperfusion pathological process.