Objective To compare the clinical efficacy among the patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) who have undergone percutaneous coronary intervention (PCI) at the different time windows, and to investigate the left ventricular cardiac function undergoing the interventional therapy at the different time windows. Methods 101 eligible patients admitted into hospital due to NSTE-ACS were recruited Randomized grouping study was used. All patients eligible and having agreed to undergo the interventional therapy were divided into two groups by means of random number table, i.e. early (24-48 h) interventional therapy group(49 cases)and delayed (≥48 h) interventional therapy group(52 cases), their basic clinical characteristic pathological changes and therapeutic processes were compared. And as a result of comparsion of their blood flow ,LVDd and LVEF in the two groups after treatment, the effects on their living quality, cardiac function and myocardial remodeling after interventional therapy at the different time windows were assessed. Results The clinical characteristics, coronary pathological changes, intraoperative complications, incidence of postoperative cardiac insufficiency, preoperative LVDd [(50.83±5.02) vs (52.15±4.79)] and LVEF [(60.98±7.06) vs (57.24±7.08)] among the patients of the two groups undergoing interventional therapy were of no statistical difference. The preoperative LVDd was not significant in the early interventional therapy group and the delayed interventional therapy group. As shown in the Results 180 days after intervention, the interventional therapy group had better LVDd with statistical significance (P＜0.05). Conclusions As compared with the delayed interventional therapy group, the early interventional therapy of NSTE-ACS improves the clinical symptoms, shortens the hospital stay and restores the left ventricular function significantly. With the follow-up prolonged, the left ventricular function and ejection fraction are significantly improved.