Objective To observe and compare the neuromuscular effects of vecuronium in young and middle-age female patient during general anesthesia.Methods A total of 40 ASA Ⅰ-Ⅱ female patients scheduled for breast mass excision were randomly assigned to two groups:young-age group 18-44 years old and middle-age group 45years old-59 years old,with 20 patients each.Vecuronium of 2 ED95 (0.1 mg/kg) was injected during anesthesia induction,using TOF-Watch acceleration monitoring instrument for muscle relaxation.Thumb adductorius contractile response was monitored with train of four(TOF) stimulation.The time of neuromuscular block onset,duration of blockade maintenance,duration of in vivo action,recovery index and the time of TOF ration of recovery to 25% were recorded.Results The muscle relaxant onset time,duration of action in vivo and TOF recovery to 25% of the time in youth group were significantly shorter than that in the middle-aged group [(156±33),(186±44) s,(67±29),(77±20),(48± 14),(60±16) min] (P<0.05).There were on significant difference in duration of blockade maintenance [(37± 10),(43± 11) min] (P>0.05)and neuromuscular block recover index [(21±17),(22±13) min](P>0.05)between two groups.Conclusions Compared to patients with middle-aged women,young female patient showed more sensitive to vecuronium with faster neuromuscular block onset,shorter duration of clinical action,but had no effect on the recovery process of muscle relaxants. Key words: Vecuronium; Age; Neuromuscular block ; Female