Background: ATP8B1 mutation is one of the factors that result in cholestasis and progress to chronic liver disease, but has never been reported in the Mainland China before. The aim of this study was to elucidate the role of ATP8B1 mutation in Mainland Chinese patients with progressive intrahepatic cholostasis and low GGT. Methods: 24 children who presented with progressive intrahepatic cholostasis and low GGT were admitted in a tertiary pediatric hospital in eastern China. ABCB11 gene was analyzed firstly to exclude BSEP deficiency. Afterwards, all the encoding exons and their flanking areas of ATP8B1 gene were sequenced in the remaining 19 patients in whom only one or no mutations of ABCB11 were found. Results: 10 mutations of ATP8B1 gene were found in 9 patients. I694N had been reported in Taiwanese patients with PFIC1, and the others were novel. P209T and IVS6+5T G were linkage and found in 4 of 9 patients, including 2 homozygote and 2 heterozygote. Liver biopsy had been performed in 6 patients with ATP8B1 mutations and 5 with ABCB11 PE408 mutations. Variety portal fibrosis was showed in 2 patients with ATP8B1 mutations and 4 patients with ABCB11 mutations. Giant cell transformation was detected in one patient with ATP8B1 mutations and 4 patients with ABCB11 mutations. 1 Laboratory of Exercise Biochemistry, Taipei Physical Education College, Jhongcheng Rd., No. 101, Sec.2, Taipei City-11153, Taiwan, ROC Background/aim: Generation of reactive oxygen metabolites are depends on the consumption of oxygen and their cumulative effects may be different from lean to obese population. This study was designed to investigate the deleterious effects of oxidants on hepatic antioxidant defence system in lean and obese rats under hypoxic condition. 