Abstract: Objective: The goal of the study was to evaluate the effect of intravenous(iv) epinephrine on coronary no-reflow during PCI （percutaneous coronary intervention）.Method: In this single center retrospective study, a total of 62 patients with no-reflow were divided into two groups.Group1（30 patients） received intravenous epinephrine when conventional treatments were ineffective during PCI, while group 2(32 patients) received intracoranay nitroprusside after conventional treatments. The clinical baseline data coronary angiographic results were analyzed in both groups ,including the change of TIMI flow grade ，the CTFC（Corrected TIMI Frame count）and blood pressure ,the mortality during hospital stay.The primary end point were the achievement of TIMI Ⅲ flow. The second end point were the occurrence of arrhythmias and major adverse cardiac events (MACEs) during hospital stay.Results： After once injection of epinephrine(mean dose 0.50±0.16mg ) ,the percentage of patients achieving TIMI Ⅲ flow in Group 1was 24( 80.0% ),while after 1.72±0.81 times injection of nitroprusside(mean dose 346.88±145.87ug) 22(68.8%)in Group 2 ，(P>0.05). The rate of coronary flow recovery to TIMI Ⅲ flow was 50% for a single application of nitroprusside, which was significantly lower than that of group 1 (P<0.05).After treatment, The final improvement of coronary flow were not significant different in both groups.But the CTFC were 26.33 ±5.55vs30.22±7.02（P<0.05）respectively. The time to restore the flow to the optimal state were 6.10±1.90vs10.84±2.82min(P<0.01)respectively. The second end points were not different in both groups.Conclusion: Intravenous epinephrine can rapidly improve the coronary flow without the increasing incidence of the MACEs during hospital stay