Objective To investigate the effect of desflurane on neuromuscular blockade of rocuronium Methods Thirty adult patients ,scheduled for selective surgery under general anesthesia, were randomly allocated to receiving intravenous propofol 4mg?mg -1 (group I,n=10),inhalation of 1MAC(6%) desflurane lasting 15 min (group Ⅱ,n=10) or 45 min(group Ⅲ,n=10) to maintain anesthesia,respectively Rocuronium 0 6 mg?kg -1 was given intravenously in group I following stable anesthesia , in group Ⅱ or group Ⅲ with the stable end tidal concentration of desflurane at 1MAC for 15 min or 45 min,respectively The onset time and degree of neuromuscular blockade were monitored with train of four(TOF) technique.Results The onset times of T 1 and TOF in group Ⅲ(1 3 and 0 8 min) were shorter than in group I(2 2 and 1 5 min)(P