Abstract: Objective: The aim of this study was designed to assess whether second harmonic with SHU-508A would improve left ventricular opacification. Methods: In 10 open chest normal dogs, an intravenous injection of SHU-508A was performed in second harmonic echocardiographic myocardial opacification and compared with pre injection by quantitative assessment of videointensity at short axis views of the papillary museles. Results: the peak intensity、 area under wash in curve、 time of intensity change and slope of wash in curve were significanly higher than the control group （both P＜0.05）. Conclusion: Second harmomic imaging with transpulmonary ultrasourd contrast agent is a safe and efficient clinical diagnostic toolfor assessing myocardial perfusion.