Objective To explore the effect of different controlled hypotension method on the blood flow of the vertebral vein by measuring of blood flow of vertebral vein in rabbits. Methods Eighteen New Zealand rabbits,weighing 2-3 kg,were rando mly divided into three groups (n =6 each).Group S maintained MAP (90±5)mm Hg,group GTN reduced MAP to the base value of (70±10)% by using nitroglycerin 0.5 μg·kg-1 ·min-1 and esmolol 2.5 μg·kg-1 ·min-1 (ni-troglycerin∶esmolol= 1∶5 ),group SNP reduced MAP to the base value of (70 ± 10 )% by using sodium nitroprusside 0.5 μg·kg-1 ·min-1 and esmolol 2.5 μg·kg-1 ·min-1 (sodium nitroprusside∶es-molol=1∶5).The controlled hypotension model was established after intravenous general anesthesia. The blood flow of vertebral vein in rabbits were measured by ultrasonic measurement system (Terason 2 000 system ) before controlled hypotension and 1 hour after controlled hypotension. Results The MAP before controlled hypotension in group S (89.0 ± 5.2 )mm Hg,group GTN (91.5± 9.6 )mm Hg,group SNP (92.0 ± 5.7 )mm Hg had no significant difference.The blood pressure before and after the experiment had no significantly difference in group S.The blood pressure after controlled hypotension had no significant difference in group GTN and group SNP,but lower than that before controlled hypotension (P <0.05).Compared with group S,the blood flow of verte-bral vein in group GTN and group SNP were significantly reduced (P < 0.05 ).The blood flow in group GTN was significantly reduced compared with that in group SNP (P <0.05 ).Conclusion In the experiment,the combination of nitroglycerin and esmolol can better reduce blood flow of vertebral vein than that of nitroprusside and esmolol,that it is suitable for the control of hypotension in spinal surgery.