Regenerated skin with 3-dimensional structure is desired for the treatment of large burn and for the plastic surgery. High frequency ultrasound is suitable for non-destructive testing of the skin model because it provides information on morphology and mechanical properties. In this paper, spectral parameters of ultrasound radio-frequency signal from a specially developed high-frequency ultrasound imaging system were evaluated for tissue characterization of artificial skin. Results suggest that spectral parameters are useful for classification of epidermis and dermis in the artificial skin model. The system is also a useful tool for the noninvasive and nondestructive evaluation of skin.