Objective: To study the intestines absorption mechanism of salidroside using signal-pass perfusion model in rats. Method: After one-way intestinal perfusion model of rat in situ was set up

by taking phenolsulfonphthalein as a marker

the absorption of salidroside in small intestine under conditions of different concentrations

segments

and pH values was studied respectively. Result: Salidroside was much stable in Krebs-Ringer(K-R) solution

pH value was 5.5-8.0. No significant difference of Peff value was found in different concentrations of salidroside at different intestine segments

which showed that there was no obvious change in absorption of salidroside in rat small intestine and no inhibition due to different concentrations and the absorption of salidroside mainly was complied with the passive diffusion. The Peff and Ka values of intestinal perfusion showed that the absorption of salidroside in duodenum

jejunum

and colon were better than that of ileum. Conclusion: Salidroside absorption in rat intestine is mainly by passive diffusion

and is easily absorbed in the intestine.