Measurements of total reflectance and transmittance for porcine nasopharyngeal tissue using single integrating sphere technique were carried out under the irradiation of He Ne laser at the wavelength of 632 8 nm, which has the advantage over conventional double sphere techniques in that no corrections are required for sphere properties. Furthermore, with the measurement of collimated transmission for optically thin slabs, the optical properties of porcine nasopharyngeal tissue in vitro were indirectly obtained by applying inverse adding doubling theoretical model. The optical properties of porcine nasopharyngeal tissue are characterized by low absorption and high scatter, and the value for absorption coefficient and scattering coefficient are 0 96 cm -1 and 62 7 cm -1 , respectively. The scattered light is highly forward as demonstrated by the mean cosine of the scattering angle, and the optical penetration depth for porcine nasopharyngeal tissue is about 0 241 cm.