Objective To evaluate the efficacy and safety of paclitaxel drug-coated balloons (DCB)in treating acute coronary syndrome in patients with high bleeding risk.Methods A total of 35 inpatients with acute coronary syndrome and high bleeding risk who were treated in our hospital from March 2017 to December 2017 were retrospectively analyzed.The patients were divided into the control group (n=20) treated with normal balloon dilatation and the experimental group (n =15) treated with DCB treatment.The age,major cardiac adverse events(MACE)within 3 months,fatal hemorrhage events,all-cause mortality,attributable mortality,target lesion revascularization rate(TLR),coronary artery stenosis degree before intervention,and coronary artery stenosis degree at once and 3 months after surgery,were used for comparison and for statistical analysis between the control and the experimental group.Results There were no significant differences between the two groups in the indexes as the followings:MACE within 3 months after surgery(25.0％ vs.6.7％,x2 =2.03,P =0.15),fatal hemorrhage events (10.0 ％ vs.6.7 ％,x2 =0.12,P =0.727),all-cause mortality (20.0％ vs.6.7％,x2 =1.24,P =0.27),attributable mortality(10.0％ vs.0.0％,x2 =1.59,P=0.21),TLR(14.3％ vs.0％,x2 =3.08,P =0.08).However,the incidence of fatal hemorrhage and MACE,all-cause mortality,attributable mortality and TLR were relative low in the experimental group (P＞0.05).Conclusions Drug-coated balloon treatment is safe and effective in treating acute coronary syndrome in patients with high bleeding risk.