Abstract: Since the improvement of microcirculation image quality is the key for the application of such devices, a novel method and apparatus for the microcirculation detection is introduced. The experiments are done with orthogonal polarization spectral imaging apparatus based on this theory and some nail-fold microcirculation images with good contrast are obtained. When linear polarized light is focused on the tissue, the light reflected from the tissue surface remains original polarization state and is blocked by the orthogonal polarization analyzer placed before CCD. The light coming back from the inner of the tissue turns up the multi-scattering and is depolarized. The image is formed after it passes through the analyzer. If the wavelength is selected properly within the absorption spectrum of red cell, clear microcirculation images can be observed.