The aim of the study is to investigate rat intestinal absorption behavior of three main active  components, schisandrol A, schisandrin A and schisandrin B in Schisandra chinensis Baill extracts in intestine of rats.  With phenol red as the indicator, in situ single pass intestinal perfusion (SPIP) model was used and the concentrations of three main active components in perfusion solution of different intestinal segments (duodenum, jejunum, ileum, and colon) were determined by HPLC in combination with diode array detection.  The results showed that the absorption rate constant (K_a) and effective permeability values (P_eff) of three main active    components in Schisandra chinensis Baill extracts had significant difference (P < 0.05) at different concentrations of perfusion solution, the K_a and P_eff first increased and then decreased with the increase of drug concentration, the middle concentration was higher than those of the other two concentrations.  The saturate absorption phenomena were observed, and it suggested that the transport mechanisms of three main active components    in vivo were similar to active transport or facilitated diffusion.  Three active components can be well absorbed in all of the intestinal segments, while duodenum is the best absorption region.  The K_a and P_eff of three active components in jejunum and ileum had no significant difference (P > 0.05).  The absorption of the three active components displayed significant difference (P < 0.05) at different intestinal segments of rats.  Schisandrin A had the best absorption in duodenum.  The K_a and P_eff among three active components were sequenced as follows: schisandrin A > schisandrin B > schisandrol A in other intestinal segments, and there is significant difference (P < 0.05) between them.