Regional anesthesia can significantly alleviate the early postoperative pain in children. But postoperative pain often lasts for several days, and a single dose block usually is not enough. Due to the children's physiological particularity, continuous regional block probably increases the risk of local anesthetic poisoning. As a result, adjuncts are often added to local anesthetics to prolong the time of regional block in children. This review focuses on the metabolic characteristics of local anesthetics in pediatric regional block, the mechanism and characteristics of common adjuncts, the application of various adjuncts in different types of regional block, safety and adverse reactions of adjuncts.