Objective To explore the effect of thiopentone, ketamine and diazepam on combined anesthesia in rabbits.Method Thiopentone(2 5%,0 6 ml/kg) was slowly injected into 116 experimental New Zealand rabbits to perform anesthesia induction,followed by intraperitoneal injection with mixture(1ml / kg) of ketamine (1 25%) and diazepam(0 125%) preoperatively.If palinesthesia and restlessness appeared, intraperitoneal injection with drugs(mixture, 1ml / kg; thiopentone,0.5 ml / kg) would be applied repeatedly.Results No rabbits died.The combined anesthesia sustained 30-45 minutes each time,and satisfied experimental operation.Conclusion Anesthesia effect can be safely and rapidly achieved by anesthesia induction combined with intraperitoneal injection.Thiopentone and ketamine show the similar anesthesia time, which can be easily controlled. The combined anesthesia is suitable for experimental operations on rabbits, such as on limbs,spine or brain.