Aim To observe and evaluate the curative efficacy of fractional flow reserve （FFR） guided percutaneous coronary intervention （PCI） for borderline coronary lesion （diameter stenosis was 50%～70%）.Methods From 2012 January to 2012 December,76 consecutive patients from our hospital with single branch borderline coronary lesion confirmed by coronary angiography （CAG） were chosen to accept FFR measurements.All the patients were divided into two groups,48 cases with FFR≥0.75 accepted only optimal medical treatment （OMT group）,28 cases with FFR＜0.75 were accepted PCI and optimal medical treatment （PCI＋OMT group）.After 12 months’ follow-up,the incidence of major adverse cardiac event （MACE） and the scores of Seattle Angina Questionnaire （SAQ） between the two groups were compared.Results There was no statistically significant difference between OMT group and PCI＋OMT group in the incidence of MACE.Compared to the baseline both groups’ scores of SAQ had significantly improved （P<0.05）.And the SAQ scores improvement had no statistically significant difference in physical limitation,angina stability,angina frequency and disease cognition level between the patients of OMT group and PCI＋OMT group.But the OMT group had more statistically significant improvement than PCI＋OMT group in treatment satisfaction level （P<0.05）.Conclusion FFR can reliably predict the risk of myocardial ischemia and guide treatment decisions for patients with borderline coronary lesion.It can avoid unnecessary PCI and effectively improve the quality of life and body function of the patients with coronary borderline lesion.