Objective To systematically review respiratory muscle training (RMT) on respiratory functions of patients with spinal cord injury (SCI). Methods PubMed, EMbase and The Cochrane Library were electronically searched to collect the randomized controlled trials (RCTs) about RMT on pulmonary functions in patients with SCI from inception to April, 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using RevMan 5.3 software. Results A total of 11 RCTs involving 263 patients were included. The results of meta-analysis showed that, compared with conventional rehabilitation group, RMT effectively improved vital capacity (MD=0.41, 95%CI 0.12 to 0.69, P=0.005), inspiratory capacity (MD=0.35, 95%CI 0.05 to 0.65, P=0.02), maximal inspiratory pressure (MD=7.75, 95%CI 0.11 to 15.39, P=0.05) and maximal voluntary ventilation (MD=17.52, 95%CI 8.11 to 26.93, P=0.000 3). There were significant differences between two groups. Conclusion Current evidence shows that RMT can effectively improve the respiratory function of patients with SCI. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify above conclusion.