Ｏｂｊｅｃｔｉｖｅ　To evaluate the effects of dexmedetomidine (Dex) by oral mucosa spray versus nasal drip in preoperative sedation in children.　Methods　Sixty children underwent minor elective surgery in the inguinal region, aged 1 to 5 y, and American Society of Anesthesiologists (ASA) grade Ⅰ. They were divided into two groups according to the random number table method： the nasal drip group （group N） and the oral mucosa spray group (group B), 30 cases in each group. The children were given Dex 1.5 μg/kg by nasal drip or oral mucosa 40 min before surgery. Heart rate, pluse oxygen saturation(SpO2) and observer assessment of alertness and anxiety scale (OAA/S) were measured before and 10, 20, 30, 40 min after administration. The drug acceptance, parental separation anxiety scale and mask acceptance scale of the two groups were observed, and the occurrence of adverse events during the post-anesthesia care unit(PACU) was recorded.　Results　Drug acceptance satisfaction in group B was higher than in group N (P＜0.05). The medicine sedation onset time was 20 min and 30 min in group N and group B (P＜0.05), there was no significant difference in OAA/S sedation scores 40 min after administration (P＞0.05). Heart rate of group N and group B decreased significantly at 20, 30 min after medication respectively (P＜0.05). There was no significant difference between the two groups in parental separation anxiety scores and mask acceptance scores (P＞0.05). No postoperative adverse reactions occurs in children during in the PACU.　Conclusions　A good sedative effect can be obtained by administration of Dex via oral mucosa spray or nasal drip route. The nasal drip mode works quickly, but it is more easily accepted by children during oral mucosa administration．