Objective To compare the anesthetic effects of interscalene brachial plexus combined with ulnar nerve and axillary brachial plexus block guided by nerve stimulator. Methods Eighty patients belonging to ASA ⅠorⅡ and undergoing replantation of severed palm or wrist were divided randomly into 2 groups, Each group had 40 patients. Nerve stimulator guided nerve block. Patients in groupⅠreceived interscalene brachial plexus combined with ulnar nerve block, and those in groupⅡreceived axillary brachial plexus block. The onset time, hold time, tourniquet tolerance of radial nerve, median nerve and ulnar nerve of two groups was recorded. The phrenic nerve block, Horner′s syndrome and recurrent laryngeal nerve block was compared between two groups. Results The onset time of radial nerve, median nerve and ulnar nerve in group Ⅰwas (5.13 ± 0.76), (7.13 ± 1.04), (3.23 ± 0.62) min , in group Ⅱ was (9.23 ± 1.61), (12.35 ± 1.76), (8.83 ± 1.13) min, and there were significant differences (P<0.05). The excellent rates of sensory block of radial nerve, median nerve and ulnar nerve in group Ⅰ were 90.0%(36/40), 85.0%(34/40), 97.5%(39/40), in group Ⅱ were 72.5%(29/40), 65.0%(26/40), 70.0%(28/40), and there were significant differences (P<0.05). The full rates of motor block of radial nerve, median nerve and ulnar nerve in groupⅠwere 75.0%(30/40), 37.5%(27/40), 80.0%(32/40), in groupⅡ were 47.5%(19/40), 40.0%(16/40), 45.0%(18/40), and there were significant differences (P < 0.05). The tourniquet tolerance rate in group Ⅰwas significantly higher than that in groupⅡ:90.0%(36/40) vs. 62.5%(25/40) , P<0.05. In groupⅠ, phrenic nerve block occurred in 2 patients, and Horner syndrome occurred in 1 patient. None had laryngeal recurrent nerve block in both group. Conclusions The interscalene brachial plexus combined with ulnar nerve block guided by nerve stimulator is more suitable for a long time microsurgery of the palm or wrist, because it takes action faster, has better sensory and motor block effects, improves the rate of tourniquet tolerance without increasing untoward reaction.