Fusarenon-X (F-X) is one of the trichothecene mycotoxins. F-X enhanced D-xylose absorption rate in rat everted intestinal sac. In the present work, the mechanism of the F-X-induced enhancement of intestinal D-xylose absorption rate was studied. F-X had no detectable effect on D-glucose absorption of everted rat intestine. When 10 mM of D-xylose was employed, a concomitant application of oxygen-free condition and low temperature failed to affect the D-xylose absorption of normal rat, but inhibited that of F-X-treated rat. When D-glucose concentration was 5 mM, the concomitant application of oxygen-free condition and low temperature depressed the D-glucose absorption of normal rat, while it did not reduce that in F-X-treated rat. These results suggested that the sugar translocation mechanism of F-X-treated rat intestine was different from that of normal one. F-X-induced enhancement of D-xylose absorption in everted intestinal sac may depend on the increase in permeability of the intestinal membrane which is derived from the histological and functional damage of the intestinal mucosa induced by F-X.