The rats were fed with the Genetically Modified Sugar Beet line 77 (Monsanto Ko, USA) 10 g/rat/day for 1 month. Their blood, urea and liver were investigated to measure total protein and glucose levels, aminotransferase and alkaline phosphatase activities, pH, creatinine level as well as hepatic enzyme activity of the I and II phases of xenobiotic metabolism and whole and non-sedimentated lysosomal enzyme activities and activity of antioxidant system.