Objective To evaluate the effects of sepsis on pharmacodynamics of rocuronium in rats.MethodsForty SD male rats weighing 250-350 g were randomly divided into 3 groups: control group(group C,n =10) ; sham operation group(group S,n =10)and sepsis group (group Sep,n =20).Cerum was ligated and perforated to produce sepsis model in Sep group,rocuronium 3.81 mg/kg was intravenously injected at 6 or 16 h after operation,each time contains 10 rats.Cecum was not ligate and perforate in group S,but rocuronium 3.81 mg/kg was intravenously injected at 6 h after operation.Onset time,TOF no reaction period,duration of peak effect,clinical duration,totel duration,time for recovery of T1 to 10％,25％,50％,75％,90％ and recovery index were recorded by RM6240B signal acquisition and processing system.ResultsCompared with groups C and S,onset time was significantly prolonged,TOF no reaction period,duration of peak effect,clinical duration,total duration and time for recovery T1 to 10％,25％,50％,75％,90％ and recovery index were shortened in group Sep ( P ＜ 0.05).Onset time was significantly prolonged,time for recovery of T1 to 75％ was shortened when rocuronium injection at 16 h after operation as compared with that at 6 h after operation in group Sep( P ＜ 0.05).ConclusionSepsis can attenuate the effects of nondepolarizing neuromuscular blocker rocuronium,the degree is related to the stage of sepsis.