OBJECTIVE： To systematically review the clinical efficacy of sildenafil in the treatment of persistent pulmonary hypertension in newborns （PPHN）， and to provide evidence-based reference in the clinic. METHODS： Retrieved from PubMed， Cochrane Library，EMBase（Ovid），CBM，CJFD，Wanfang and VIP， randomized controlled trials （RCTs） about sildenafil （test group） versus basic therapy or placebo in the treatment of PPHN were collected. Meta-analysis was performed by using Rev Man 5.1 software after data extraction and quality evaluation by Cochrane 5.1.0. RESULTS： Totally 6 RCTs were enrolled， involving 210 patients. Results of Meta-analysis showed， compared with placebo， sildenafil can significantly reduce the mortality [RR＝0.16，95％CI（0.05，0.45），P＜0.001] and the oxygenation index [after 2 h：MD＝－12.80，95％CI（－20.11，－5.49），P＜0.001；after 24 h：MD＝－19.41，95％CI（－24.81，－14.00），P＜0.001]， with statistical significances； compared with basic therapy， sildenafil can significantly reduce pulmonary arterial pressure [after 2 h：MD＝－22.36，95％CI（－24.89，－19.83），P＜0.001； after 24 h：MD＝－29.43，95％CI（－31.12，－27.74），P＜0.001]， with statistical significances， but there was no statistical difference in mortality[RR＝0.64，95％CI（0.30，1.39），P＝0.26]. CONCLUSIONS： Sildenafil is effective in the treatment of PPHN， it can significantly reduce the oxygenation index， pulmonary arterial pressure and mortality.