Objective To compare the application effects of pentobarbital sodium ,urethane and midazolam combined with ket-amine/Sumianxin Ⅱ in rabbit bone defect repair .Methods 120 healthy male adult rabbits were randomly divided into three groups according to different anesthetic agents ,40 cases in each group .The group A was intramuscularly injected by pentobarbital sodium , the group B was given urethane by the ear vein and the group C was given midazolam combined with ketamine/and Sumianxin Ⅱ by intramuscular injection .The onset time of anesthesia ,maintenance time ,breathing rate ,heart rate ,complications ,recovery time ,ad-ditional anesthetic agents and postoperative death rate in 3 groups were recorded respectively .Results The onset time of anesthesia in the group B and C was(4 .53 ± 0 .65) min and(3 .56 ± 1 .31) min respectively ,which were significantly shortened compared with the group A(P<0 .05);the maintenance time of anesthesia in the group B was (152 .12 ± 12 .53) min ,which was significantly short-ened compared with the group A and C (P<0 .05);the recovery time in the group C was (31 .05 ± 5 .73) min ,which was significant-ly shortened compared with the group A and B(P<0 .05) ,the propability of additional anesthetic agents and the postoperative mor-tality in the group C were significantly decreased compared with the group A and B (P<0 .05) .Conclusion The combined anesthe-sia of midazolam and ketamine/Sumianxin Ⅱ has definite effect without any observed intraoperative depressions of breathing rate and heart rate and with high safety ,high controllability and less influence on the long term survival of the experimental animals , which is a more ideal anesthesia method of the rabbit bone defect repair .