Objective To compare the effectiveness of oral administration and intravenous injection of midazolam for preoperative sedation in pediatric surgery. Methods A total of 261 children, aged 2‒10 years, American Society of Anesthesiologists (ASA) grade Ⅰ, who were scheduled for eye, ear, nose and throat (EENT) surgery were enrolled. According to their routes of administration, they were divided into two groups: an oral administration of midazolam 0.5 mg/kg group (the oral group, n=143) and an intravenous injection of midazolam 0.05 mg/kg group (the IV group, n=118). Their modified Yale Preoperative Anxiety Scale (mYPAS) scores and Sedation Scale (SS) scores were evaluated before administration, and 10 min and 20 min after administration. The degree of patient compliance before preoperative visit (green, yellow and red labels) was recorded. Meanwhile, parent education background scores, parents' self‑evaluation anxiety scores, the Parental Separation Anxiety Scale (PSAS) scores and the Mask Acceptance Score (MAS) as well as the time of drug onset, clinical manifestation after drug onset, recovery time and the quality of recovery were recorded. Both groups were compared for the above indicators, while the effects of the above two administration methods were evaluated. Results The oral group presented smaller age and less body weight than the IV group (P<0.05). Compared with the IV group, the oral group presented remarkable increases in the time of drug onset and recovery time (P<0.05); remarkable increases in the scores of activity, vocalization, emotional expressivity, state of arousal, and the use of parents within the mYPAS score before administration (P<0.05); remarkable increases in the scores of activity, vocalization and emotional expressivity within the mYPAS scores 10 min after administration (P<0.05); and remarkable increases in the scores of activity and the use of parents within the mYPAS scores 20 min after administration (P<0.05). Furthermore, the oral group produced significantly lower SS scores before and 10 min after administration (P<0.05), less green, yellow and red labels (P<0.05), and higher quality of recovery than the IV group (P<0.05). There was no statistical difference in other indexes between the two groups (P>0.05). Conclusions Oral administration and intravenous injection of midazolam can effectively relieve anxiety in children before EENT surgery. Oral administration of midazolam has more advantages for younger children without venous access. Results This was a semi - blind and semi - randomized controlled study. There was no significant difference in gender and BMI between the two groups. The age of the children in Oral group (4.34 ± 1.19) was about 1 year younger than that in IV group (5.38 ± 2.02), the mYPAS score was higher (P 0.05) and the SS score was lower (1.76 vs 2.25，P0.05) before and 10 minutes after administration of midazolam. There was no significant difference in parent education levels and anesthesia recovery quality, separation SS and MAS between the two groups. The onset time, separation time and recovery time in Oral group were 15.37 ± 8.61 minutes, 29.30 ± 20.09 minutes and 65.81 ± 22.65 minutes, and those in IV group were 6.84 ± 5.10 minutes, 28.48 ± 25.40 minutes and 52.12 ± 16.35 minutes, respectively. The recovery quality in the Oral group was slightly better than that in IV group (P 0.05).