Objective To retrospectively analyze the clinical effect of thrombus aspiration combined with PCI for STEMI patients with high thrombus burden. Methods 150 STEMI patients with high thrombus burden in hospital were enrolled. According to whether undergoing thrombus aspiration treatment during the course of PCI, patients were divided into PCI alone (Control group, n=72) and thrombus aspiration combined with PCI group (observation group, n=78). We recorded for general information, infarct related artery, number of diseased vessels, thrombosis in myocardial infarction (TIMI) flow grade before PCI and thrombosis load grade. The peak value of CKMB, sumSTR 2 hours postPCI, TIMI myocardial perfusion grade (TMP), LVEF and LVDD 5~7 days after PCI and the incidence of major cardiovascular adverse events during hospitalization were collected. All data was analyzed by SPSS 18.0 software. Results There were no significant differences between patients of observation group and control group in characteristics at baseline, infarctrelated artery, the number of diseased vessels, the peak value of CK-MB, thrombosis in myocardial infarction (TIMI) flow grade and thrombosis load grade before PCI. The sum-STR≥ 70% (81.58% vs 68.09%), postoperative TMP grade 3 (78.95% vs 49.65%) and LVEF (59.56±7.16 vs 57.26±8.55) in observation group were higher than that in control group (P＜0.05). The percentage of major adverse cardiovascular events in observation group was lower than that in control group (P＜0.05).Conclusion Thrombus aspiration combined with PCI for STEMI patients with high thrombus burden can relieve cardiac function and improve recentterm prognosis.