Objective:Approach effect of sevoflurane of different concentrations on vecuronium muscle relaxation.Methods:Eighty pa-tients scheduled for abdorminal surgery were divided randomly into four groups:comparison group(group 1)

inhalating sevoflurane with 1 MAC(group 2)

1.5 MAC(group 3)or 2 MAC(group 4).The effect of sevoflurane with different MAC on vecuronium muscle relaxation were observed.Inhibiting time

T1 recovery time and recovery index in four groups after vecuronium injection were recorded.Results:There was no significant difference in inhibiting time between group 1 and group 2(P>0.05)

and that in group 3 or group 4 was obviously shorter than in group 1(P<0.05).The number of T125%

T175%and recovery index in gourp 3 and gourp 4 was notably bigger than that in group 1(P<0.05).Conclusion:Inhalating over 1.5 MAC sevoflurane strengthens vecuronium muscle relaxation and prolongs its effecting time.