Regenerated skin with complete organ structure is desired for the treatment of large burn and for the plastic surgery. High frequency ultrasound is suitable for nondestructive testing of such skin models because it can obtain both morphological and biomechanical information in non-invasive manner. A specially developed acoustic microscope system with the central frequency of 100 MHz was developed for evaluation of regenerated skin. The system was capable of (1) conventional C-mode acoustic microscope imaging of thinly sliced tissue, (2) ultrasound impedance in vivo imaging of the surface of tissue and (3) 3D ultrasound imaging of in vivo tissue. Sound speed in C-mode showed higher values at the area of dense fibroblasts in collagen sponge. The system can be used as the in vitro nondestructive evaluation tool in the process of regenerating skin and as the in vivo diagnostic system after implantation of the skin.