Objective:To systematically evaluate the clinical efficacy of programmed death-1 and programmed death ligand 1 (PD-1/PD-L1) inhibitors versus traditional first-line regimens for the treatment of solid tumors.Methods:Databases including PubMed, Embase and Cochrane Library were searched for literatures from the date of their establishment to October 2018 with the key words including "PD-1/PD-L1, solid tumors, melanoma, non-small cell lung cancer, renal cell carcinoma, immunotherapy" . The randomized controlled trial or non randomized controlled trial of high quality about PD-1/PD-L1 inhibitors and traditional fist-line regimens for the treatment of solid tumors were received and enrolled. Patients underwent PD-1/PD-L1 inhibitors immunotherapy were allocated into treatment group, patients underwent traditional first-line regimens treatment were allocated into control group. Two reviewers independently screened literatures, extracted data and assessed the risk of bias. Count data were described as odds ratio ( OR) and 95% confidence interval (95% CI). The heterogeneity of the studies included was analyzed using the I2 test. Funnel plot was used to test potential publication bias if the studies included≥5, and no test was needed if the studies included<5. Results:(1) Document retrieval: a total of 11 available randomized clinical trials were included. There were 5 161 patients, including 2 677 in the treatment group and 2 484 in the control group. (2) Results of Meta analysis. ① There was a significant difference in the objective response rate between the treatment group and the control group ( OR=4.49, 95% CI: 3.01-6.68, P<0.05). The bilateral symmetry was presented in the funnel plot based on the 9 studies, suggesting that publication bias had little influence on results of Meta analysis. ② There was no significant difference in the disease control rate between the treatment group and the control group ( OR=1.53, 95% CI: 1.01-2.32, P=0.05). The bilateral symmetry was presented in the funnel plot based on the 9 studies, suggesting that publication bias had little influence on results of Meta analysis. ③ There was a significant difference in disease stability rate between the treatment group and the control group ( OR=0.49, 95% CI: 0.33-0.73, P<0.05). The bilateral symmetry was presented in the funnel plot based on the 9 studies, suggesting that publication bias had little influence on results of Meta analysis. ④ There was no significant difference in disease progression rate between the treatment group and the control group ( OR=0.71, 95% CI: 0.45-1.15, P>0.05). The bilateral symmetry was presented in the funnel plot based on the 9 studies, suggesting that publication bias had little influence on results of Meta analysis. ⑤ There were significant differences in overall incidence of adverse events and incidence of adverse events not less than three levels between the treatment group and the control group ( OR=0.53, 0.54, 95% CI: 0.38-0.74, 0.31-0.93, P<0.05). The bilateral symmetry was presented in the funnel plot based on the 11 studies, suggesting that publication bias had little influence on results of Meta analysis. Conclusion:Compared with traditional first-line regimens treatment, PD-1/PD-L1 inhibitors immunotherapy can improve the objective response rate and decrease the incidence of adverse events.