The preparation and properties of Harmine - gelatin microspheres ( HM - GMS) were reported. The characteristics of pharmacokinetics and embolization effects of HM - GMS in vivo were studied in dogs. The average diameter of the microspheres was 63. 0μm and the content was 6.09% of HM. In in vitro experiment, the release rate of drug demonstrated that the microspheres had sustained - release properties. The HM - GMS and HM solution were infused into the hepatic artery of dogs through a catheter for embolization, respectively. The plasma concentration of HM was determined by HPLC. The peak concentration of HM solution was 2.9 times as much as HM - GMS in circulating blood, while that of solution was 0.42 times as much as HM - GMS in hepatic vein. Angiograms revealed that the peripheral blood vessels decreased obviously in liver. Results showed that the HM - GMS probably can become a promising embolic agent for treatment of hepatic cancer. It could aid in the use of intensive chemotherapy with minimum systemic side effect.