Objective To study the effects and safety of thrombus aspiration catheter on myocardial reperfusion in case of slow flow or no-reflow during percutaneous coronary interventions(PCI) in patients. Methods Fifty-six patients exhibited slow flow or no-reflow during PCI in this hospital from April 2009 to April 2012. They were randomly divided into aspiration group (26 cases) and control group (30 cases).TIMI flow grade, TIMI myocardial perfusion (TMP)grade, myocardial enzymes(CK, CK-MB) values, left ventricular ejection fraction(LVEF), incidence of ischemic ST segment elevation and main adverse cardiovascular event (MACE) during 30 days follow-up after operation were compared. Results The differences in TIMI, TMP, CK, CK-MB, LVEF and incidence of ischemic ST segment elevation between the two groups were statistically significant(P<0.05), and the aspiration group was superior in these aspects to the control group, but no significant difference was found in MACE(P>0.05). Conclusions The use of thrombus aspiration catheter in case of slow flow or no-reflow during PCI is an effective method to increase distal myocardium perfusion of criminal vessel, improve heart function after operation and relieve myocardial damage due to slow flow or no-reflow.