In experiment on rats, using perfusion technique of small intestine, xylitol absorption and its influence on water and glucose absorption was determined. Perfusion fluid contained from 2.5 g to 20 g of xylitol and 2 g of glucose per liter. Quantitatively, xylitol absorption increased with the increase of this substance in perfusion liquid. However, relative absorption was the same in all groups and amounted 19-20% of xylitol incorporated to the beginning of the small intestine . Introduction of substance possessing osmotic properties to perfusion fluid caused decrease of water and glucose absorption.Addition of xylitol to liquid resulted in significant lowering of glucose absorption from 80.8 g/h/rat in control group to 60.8 g/h/rat in group with the greatest amount of xylitol. Dose-dependent decrease of water absorption from 12 ml/h/rat in control group to 0.17 ml/h/rat in group containing the highest amount of xylitol in perfusion liquid was recorded.