Objective To evaluate the efficacy of ultrasound-guided continuous brachial plexus block for analgesia after fixation of upper extremity fractures in the pediatric patients.Methods Sixty American Society of Anesthesiologists physical status Ⅰ pediatric patients of both sexes,aged 3-10 yr,weighing 13-46 kg,with body height of 97-152 cm,scheduled for open reduction and internal fixation of distal humeral fractures,were selected and divided into 2 groups (n =30 each) using a random number table:intravenous analgesia group (group Ⅴ) and continuous brachial plexus block group (group B).Surgery was completed under brachial plexus block combined with general anesthesia in the two groups.At the end of surgery,patient-controlled intravenous analgesia was used in group Ⅴ,and continuous brachial plexus block was performed with 0.1％ ropivacaine 250 ml (background infusion 0.1 ml · kg-1 · h-1,bolus dose 0.2 ml/kg,lockout interval 30 min) in group B.Tramadol was given as rescue analgesic when necessary.Ramsay sedation scores were assessed and recorded at 2,4,8,12,24,36 and 48 h after surgery,and the development of over-sedation was recorded.The require,nent for rescue analgesics and development of respiratory depression,dizziness,nausea and vomiting,pruritus and urinary retention during analgesia were recorded.The development of adverse reactions such as vascular and nerve injury,local hematoma and pneumothorax was recorded in group B.Family's satisfaction with analgesia was assessed and scored.Results Compared with group Ⅴ,Ramsay sedation scores at 2-12 h after surgery,the incidence of oversedation,nausea and dizziness and requirement for tramadol were significantly decreased (P＜0.05),and no significant change was found in the degree of family's satisfaction with analgesia in group B (P＞ 0.05).The adverse reactions such as vascular and nerve injury,local hematoma or pneumothorax were not found in group B.Conclusion Ultrasound-guided continuous brachial plexus block can be safely and effectively used for analgesia after fixation of upper extremity fractures in the pediatric patients.