Abstract: The effect of the transducer eccentricity on grayscales of intravascuair ultrasound (IVUS) images was cor- rected based on the scattering properties of high frequency ultrasound in vessel walls. The displacement and strain distributions of vessel walls produced by tissue microelement motion were obtained using a novel motion estimation method in steps and sum based on the optical flow and genetic algorithm, Furthermore, authors fort time reconstructed "real" elasticity distribution images of cross section tissues of vessel walls in the world. In vitro experimental results of porcine artery demonstrated the methods mentioned above are reasonable. Experimental investigation of vascular mechanics can be advanced to 2D sub-millimeter microstructure levels. These studies have potential to provide new technology means in monitoring and evaluation of Percutaneous Transluminal Coronary Angioplasty (PTCA) process.