OBJECTIVE: To evaluate the efficacy and safety of ambroxol in the prevention of respiratory distress syndrome (RDS) in preterm infants. METHODS: Electronic searches were performed in the Cochrane Library, PubMED, EMBASE, Chinese CBM, Chinese VIP Database, Chinese Wanfang Database and Chinese CNKI Database up to the year of 2009 for randomized controlled trials (RCT) on ambroxol for the prevention of RDS in preterm infants. The meeting articles related to the RCT were manually searched in Pediatrics and Pediatric Research. Meta analysis was performed for the results of homogeneous studies by the Cochrane Collaboration′s software RevMan 5.0.17. RESULTS: Six RCTs involving 823 preterm infants were included, and the quality assessment for the trials demonstrated 1 article as A class, 1 article as B class and 4 articles as C class. The Meta analysis showed that ambroxol administration significantly reduced the incidence of RDS (OR=0.24, 95%CI: 0.15 - 0.64, P＜0.01), bronchopulmonary dysplasis (BPD, OR=0.41, 95%CI: 0.23 - 0.75, P＜0.01), intraventricular hemorrhage (IVH, OR=0.39, 95%CI:0.24 - 0.64, P＜0.01), patent ductus arteriosus (PDA, OR=0.33, 95%CI: 0.17 - 0.67, P＜0.01) and pulmonary infection (OR=0.24, 95%CI:0.14 - 0.38, P＜0.01). No adverse events related to the ambroxol treatment were reported. CONCLUSIONS: The current evidence shows that early use of ambroxol can reduce the risk of RDS, BPD, IVH, PDA and pulmonary infection in preterm infants.［Chin J Contemp Pediatr, 2010, 12 (11):858-863］