It was found that taurocholic acid and glycocholic acid, the bile components, had the effect of accelerating absorption of salicylic acid derivatives from rat digestive tract, same as taurine and glycine reported previously. In order to examine the action of bile juice itself in the absorption of salicylic acid derivatives, experiments were carried out by ligation of bile duct (in rats) and it was found that the secreted bile had the reverse effect of inhibiting the absorption of salicylic acid derivatives from rat small intestine, and that cholic acid among the bile components had the same effect. It was thereby assumed that bile juice and bile components had repulsive and homologic actions, and were in complicated correlation. The bile juice once taken out of a living body has a different action from bile juice in secreting state and had no action of inhibiting the absorption of salicylic acid derivatives from small intestine (of a rat).