To study the in situ intestinal absorption kinetics of flrubiprofen in rats, the absorption of flurbiprofen in small intestine (duodenum, jejunum and ileum) and colon of rats was investigated using in situ single-pass perfusion method and the drug content was measured by HPLC.  The effects of drug concentration on the intestinal absorption were investigated.  The K_a and P_app values of flurbiprofen in the small intestine and colon had no significant difference (P > 0.05).  Drug concentration (4.0, 10.0 and 16.0 mg·L⁻¹) had no significant influence on the K_a values (P > 0.05).  However, when concentration was 4.0 mg·L⁻¹ and 10.0 mg·L⁻¹, significant effect on the P_app values (P < 0.05) was found, but significant effect on the P_app values was not shown between 10.0 mg·L⁻¹ and 16.0 mg·L⁻¹ (P > 0.05).  The K_a and P_app values of flurbiprofen on the perfusion flow rate had significant difference (P < 0.05).  Flurbiprofen could be absorbed at all segments of the intestine in rats and had no special absorption window.  The absorption of flurbiprofen complies with the facilitated diffusion in the general intestinal segments, and accompany with the cytopsistransport mechanism probably.  The perfusion flow rate had significant effect on the K_a and P_app.