Objective To compare the effects of penehyclidine hydrochloride, atropine and scopolamine as the preanesthetic medication before operation for patient with cleft lip/palate（CL/P） who would undergo general anesthesia. Methods 120 CL/P patients who would undergo general anesthesia with tracheal intubation as research objects were chosen. The patients were divided into three groups randomly, group of penehyclidine hydrochloride （group PH）, group of atropine（group ATR） and group of scopolamine（group SCO）, 40 patients in each group. Penehyclidine hydrochloride（0.01 mg/kg）, atropine（0.01 mg/kg）or scopolamine（0.006 mg/kg）was given respectively to the patients. The changes of heart rate, temperature, blood pressure and the secretion of respiratory tract were observed before medication, 15 minutes and 30 minutes after medication, after trachea cannula and after operation. Results There were no significant changes in heart rate, temperature and blood pressure in group PH after medication（P > 0.05）. The heart rate and temperature in group ATR and group SCO increased significantly after medication（P0.05）. The secretion of respiratory tract was decreased significantly in group PH comparing to group ATR and group SCO when the operation was over（P
