An intestinal absorption test with the use of D-xylose has been performed on 19 patients including 3 of acute hepatitis, 7 of chronic hepatitis and 9 of liver cirrhosis, and the following results were obtained. 1) The 5 hr urinary excretion and 2 hr blood level of D-xylose tend to increase in patients of acute and chronic hepatitis with severer disorder of liver functions. 2) The standard deviations of the 5 hr urinary excretion and 2 hr blood level of D-xylose are larger in liver cirrhosis than in the other liver diseases. Those cases having severe disorder of liver functions are found to be diminished in 5 hr urinary excretion and 2 hr blood level of D-xylose. 3) A decrease in the absorption of D-xylose from the small intestine of liver cirrhosis might be caused by the diminished surface area of villi of the small intestine.</p