Objective: To study the transport behavior of aconitine in the Caco-2 cell monolayer model. Method: MTT method was employed to confirm the safe concentration of aconitine towards Caco-2 cell.Aconitine concentrations in the samples were analyzed by high performance liquid chromatography (HPLC).The apparent permeability(Papp)value and the total amount of transport were calculated. Bi-direction transport behavior of aconitine by incubating in different concentration and time were studied. Result: The transport amount of aconitine was positively correlated with the incubation time and drug concentration on the Caco-2 monolayer model. The Papp values in both apical to basal (AP-BL)and basal to apical (BL-AP) directions were stable with no significant differences in selected concentrations. The BL-AP flux of aconitine was more than 1.5-fold higher than AP-BL flux(Papp 1×10-5cm·s-1). Conclusion: The results suggested that the aconitineis well absorbed through the Caco-2 monolayer model by a passive transportation. Besides

efflux protein may be involved in the transport process.