Abstract: OBJECTIVE To study the dynamic characteristics of intestinal absorption of calycosin using signal-pass perfusion model in rats. METHODS After one-way intestinal perfusion model of rat in situ was set up，by taking phenolsulfonphthalein a maker，the absorption characteristics of different intestinal segments. RESULTS Calycosin have a good stability separately in different intestinal segments and in the colon to absorb the best. Different concentrations of drug in the colon absorption in inhibition of its concentration. CONCLUSION Calycosin is well absorbed in the small intestine and calycosin absorption may active transport.