AIM: To study and determine the resting energy ex- penditure (REE) and oxidation rates of glucose, fat and protein in severe chronic hepatitis B patients. METHODS: A total of 100 patients with liver diseases were categorized into three groups: 16 in the acute hepatitis group, 56 in the severe chronic hepatitis group, and 28 in the cirrhosis group. The REE and the oxidation rates of glucose, fat and protein were as- sessed by indirect heat measurement using the CCM-D nutritive metabolic investigation system. RESULTS: The REE of the severe chronic hepatitis group (20.7 ± 6.1 kcal/d per kg) was significantly lower than that of the acute hepatitis group (P = 0.014). The respiratory quotient (RQ) of the severe chronic hepatitis group (0.84 ± 0.06) was significantly lower than that of the acute hepatitis and cirrhosis groups (P = 0.001). The glucose oxidation rate of the severe hepatitis group (39.2%) was significantly lower than that of the acute hepatitis group and the cirrhosis group (P < 0.05), while the fat oxidation rate (39.8%) in the severe hepatitis group was markedly higher than that of the other two groups (P < 0.05). With improve- ment of liver function, the glucose oxidation rate in- creased from 41.7% to 60.1%, while the fat oxidation rate decreased from 26.3% to 7.6%. CONCLUSION: The glucose oxidation rate is signifi- cantly decreased, and a high proportion of energy is provided by fat in severe chronic hepatitis. These re- sues warrant a large clinical trail to assess the optimal nutritive support therapy for patients with severe liver disease.