Objective To evaluate the clinical effectiveness of Smecta versus Xilei Powder in treatment of oral ulcer in children.Methods CBM, CNKI, VIP and WanFang Data were searched for the randomized controlled trials (RCTs) of Smecta versus Xilei Powder in treatment of oral ulcer in children from the date of their establishment to June 31, 2010. The bibliographies of the included studies were searched, too. Two reviewers evaluated the quality of the included RCTs and extracted data critically and independently, and then the extracted data were analyzed by using RevMan 5.1 software. Results Twenty-two RCTs involving 1 489 patients meeting the inclusion criteria. The results of meta-analyses showed that compared with Xilei Powder, Smecta could increase the total effective rate by 1.38 times (RR=1.38, 95%CI 1.31 to 1.45, Plt;0.000 01) and decrease the average course of treatment (MD= –1.54, 95%CI –1.77 to –1.31, Plt;0.000 01), with significant differences. Only 3 RCTs mentioned adverse events, but no adverse events were reported. Conclusion The current evidence shows that Smecta is effective and safe in treatment of oral ulcer in children. Due to the limitations of the included RCTs, the quality of outcomes are moderate based on GRADE, which should be recommended by clinicians as “Weak Recommendation”. More large-sample and high-quality RCTs are needed to confirm the reliability of this study.