Objective To evaluate the effect of midazolam alone on sedation in young children for dental restorative care.Methods Forty children, aged 5 to 10 years with a mean age of 7.3 years, participated in this study. Twenty-one patients were assigned to intervention group received 0.5 mg/kg of oral midazolam 20 minutes prior to the beginning of dental treatment, and 19 patients in control group received placebo liquid 20 minutes before treatment. All patients received painless local anesthetic injection and were restrained with children's board and bands. Blood pressure (BP),heart rate (HR), oxygen saturation, treatment compliance scores of the Ramsay scale, the Briekopf and Buttner scale,Frankl scale, and the Houpt scale were recorded. Each procedure was taped and all the data were evaluated every 5 minutes by an anesthetist or experienced dentist who was unaware of the drug given to the child.Results HR in intervention group (82.5±5.1bpm) was much lower than that in control group ( 95.2±8.9 bpm; F=31.20, P＜0.001). Intervention group had a significantly lower systolic BP level (94.8 ± 5.6 mm Hg) than control group (98.5±5.5 mm Hg; F=4.34, P=0.04), but the diastolic BP (63.0±3.5 mm Hg) was not significantly lower than control group (65.5±4.8 mm Hg; F=3.31, P=0.07 ). Children in intervention group showed more compliance. The patients' scores of the Ramsay scale, Briekopf and Buttner scale, Frankl scale, and Houpt scale in intervention group (1.37±0.96, 1.37±0.83, 1.32±0.67, and 2.32±1.49, respectively) were significantly lower than those in control group (3.71±1.23, 2.71±0.96, 2.71±0.90, and 4.71±1.19; F=44.66, 22.36,30.39, and 31.88, respectively, all P＜0.001 ).Conclusions Oral midazolam alone is safe and produces effective sedation for the dental treatment of young children. Oral midazolam application should be generally preferred because it is more easily accepted by pediatric patients.