Objective:To evaluate the efficacy and safety of ranolazine in the treatment of diabetes mellitus type 2 (T2DM). Methods:CENTRAL,Medline,EMbase,CNKI,VIP,CBM,Wanfang database,WHO Clinical Trials Registry Platform and ClinicalTrials.gov were searched. The quality of included randomized controlled trials was assessed according to the Cochrane Collaboration system review,and then Meta-analysis was performed using RevMan 5.2. Results:A total of 7 randomized controlled trials(RCTs) were enrolled in-cluding 3 131 patients. Meta-analysis showed that ranolazine(1 000 mg bid) monotherapy compared with placebo resulted in a signif-icant reduction in HbA1c(MD=-0.55,95%CI=-0.73 to -0.37,P=0.000),in FPG(SMD=-0.19,95%CI=-0.37 to -0.01,P=0.04),in 2hPG(SMD=-0.34,95%CI=-0.53 to -0.15,P=0.000 5). As an add-on interaction with antidiabetes compared with placebo,ranolazine(1 000 mg bid) resulted in a significant reduction in glycosylated hemoglobin(HbA1c)(MD=-0.47,95%CI=-0.62 to -0.32,P=0.000),a similar reduction in fasting blood-glucose (FPG)(SMD=-0.00,95%CI=-0.21 to 0.20,P=0.97),in postprandial 2 hours blood glucose(2hPG)(SMD=-0.12,95%CI=-0.33 to 0.09,P=0.28),ranolazine(750 mg bid) resulted in a significant reduction in HbA1c(MD=-0.48,95%CI=-0.85 to -0.11,P=0.01),a similar reduction in FPG(SMD=0.11,95%CI=-0.26 to 0.48,P=0.57). When add-on to antidiabetes ranolazine(500 mg bid) compared with trimetazidine elicited a similar reduction in HbA1c(MD=-0.30,95%CI=-1.35 to 0.75,P=0.58),in FPG(SMD=-0.36,95%CI=-0.94 to 0.22,P=0.22),in 2hPG(SMD=0.15,95%CI=-0.42 to -0.73,P=0.60). Ranolazine didn’t increase the risk of hypoglycemia(RR=1.24,95%CI=0.80 to 1.93,P=0.34). Conclusion:Ranolazine can effectively reduce HbA1c level by inhibiting glucagon secretion and safe for adults with T2DM.