Objective To study the clinical value of intraoperative epicardial echocardiography ( IEE) in assessing graft-left anterior descending artery ( LAD ) of off-pump coronary artery bypass grafting ( OPCABG) . Methods IEE was used to detecte graft vessels anastomosis in 53 patients with OPCABG-LAD . Two-dimensional grey ultrasound and color Doppler ultrasound was used to show whether there was abnormal echo in proximal and distal lumen , measuring diameter and rate of stenosis . Pulse Doppler ultrasound was used to observe the blood flow spectrum . Intraoperative transient blood flow meter (TTFM) was employed to measure the pulsatility index and flow volume . Results Among the 53 patients with OPCABG-LAD ,38 cases were left internal mammary artery graft (LIMA) ,15 cases were saphenous vein graft (GSV) . Pulsatility index and flow volume showed normal by TTFM . The detection rates of graft vessels-LAD anastomosis in proximal and distal segment were 100％ using IEE , including 10 cases anastomotic plaques and 10 cases proximal plaques . Comparison of blood flow parameter of graft by IEE and TTFM in operation ,there was no significant difference in LIMA grafts ( P =0 .091) ,but the correlation was statistically significant ( r = 0 .809 , P < 0 .001 ) ;the difference in GSV grafts had no statistical significance ( P = 0 .821 ) ,but the correlation was statistically significant ( r = 0 .684 , P = 0 .005 ) . Conclusions IEE clearly displays the lumen of graft vessel and LAD ,and measures the hemodynamic indexes . It provides an intuitive ,accurate and convenient method for detecting the patency of the graft vessels during OPCABG .