Changes in heart rate during reversal of neuromuscular block have been a subject of clinical investigation for manly years. A number of studios have compared the effect used anticholinergica and anticholineaterase. In most studies, the druga were administered separately or simultaneously. Furthermore these studios have ignored any possible affects that the general inhalation aneathetics used during surgery might have had during reversal of neuromusclar Block. Recently, the volatile anesthetics which mar hove a significant role in heart rate during administration of atropine and neostigmine were reported. This study was undertaken to investigate those effects of halothane and enflurane on heart rate chances during reversal of neuromuscular b1ock with glycopyrrolate (0.7 ug/kg) and pyridoatigmine (0.2 mg/kg) which was given either separately or simultaneously have been used on 40 cartes at Depatment of Anesthesiology, Hanyang University Hospital from October 1985 to June 1786. The results were as follows : 1) There were not a significant differences on age, height and weight in compare with subgroups. 2) The changes of systolic and diastolic blood pressure were not a significant statistica-llr in compare with subgroups. 3) The changes of heart rate were showed that Initial increasing and decreasing of base-line level at 10 minutes were statistically significant in compare with subgroups. (p<0.0001) 4) Tachycardia were observed as following sequence; E : G --> P>E:G +P>H : G+P > H : G --> P and bradycardia were as following sequence; H : G --> P>H : G+P>E : G --> P=E : G+P.