Objective To continuously draw blood from caudal vein of SD rats which controlled by the homemade holder with an im-proved method, and the effects of this method was evaluated according to the relevant indicators. Methods The 24 SD rats should be drew the blood from the caudal vein by the improved disposable infusion needle and supplied physiological saline at the condition of ether inhala-tion anesthesia and once a day until to the thirteenth day,and then the times of draw blood and the number of survival rats only to calculate the success rate and survival rate of rats were record. Results In the 12 days,the tail vein blood of 24 SD rats were successfully collected. But a rat died of excessive ether inhalation anesthesia on the thirteenth day. The success rate was 99. 68% and the rat survival rate was 95. 83%. Conclusion The method that applying an improved disposable infusion needle and supplying physiological saline is safe and ef-fective,flexible and convenient,which is suitable for experimental study that needs to draw blood from caudal vein of the SD rat at the contin-uous time.