ObjectiveTo assess the efficacy and safety of low-(10 mg) and high-dose (20 mg) of recombinant tissue typeplasminogen activator (rt-PA) catheter-directed thrombolysis for lower limb ischemia by using meta-analysis. MethodsThe literatures of randomized clinical trials (RCT) concerning low-versus high-dose rt-PA catheter-directed thrombolysis for lower limb ischemia study were searched using the national and international electronic databases.The literatures were screened and quality evaluated according to the inclusion and exclusion criteria, and analyzed by using the Cochrane Center the RevMan 5.2 software. ResultsA total of 4 RCT studies, with a total of 360 patients (192 patients in low dose group and 168 patients in high-dose group) were included.No statistical difference were noted in low-versus high-dose group with regard to ankle-brachial index (RR=0.20, 95%CI=-0.43-0.02, P=0.07), 30 days amputation-free survival (RR=1.00, 95%CI=0.94-1.08, P=0.91), 6 months the probability of restenosis (RR=1.00, 95%CI=0.60-1.67, P=1.00), and the incidence of groin hematoma (< 5 cm, RR=1.24, 95%CI=0.56-2.77, P=0.59).But the incidence of bleeding and the incidence of stress ulcer in low-dose group were lower than those in high-dose group (RR=2.38, 95%CI=1.10-5.15, P=0.03;RR=2.49, 95%CI=1.21-5.13, P=0.01). ConclusionTwo doses of rt-PA treatment of limb ischemia similar efficacy, but the incidence of low-dose regimen of complications is significantly lower than the high dose regimen.