The diffuse reflectance and transmittance of rabbit arteries and veins were studied at 496.5 nm wavelength of Ar+ laser and by two standard integrating sphere systems. The ex- perimented data of absorption coefficient, scattering coefficient and the changes of total optical intensities I(x), forward scattering flux i(x), backward scattering flux j(x) as a function of thick- ness of rabbit arteries and veins were evaluated and analyzed by Kubelka-Munk model. The results showed significant difforence of diffuse reffectance and transmittance between arteries and veins, the absorption coefficient of arteries were obviously lesser than that of vein, and the scat- tering coefficient of arteries were obviously bigger than that of veins. The changes of total optical intensities I(x), forward scattering flux i(x), backward scattering flux j(x) versus thickness of rabbit arteries and veins were also significant difference.