Detection of interactions between light and biological material can be used to characterize the optical properties of the biological material. The purpose of this paper is to develop a method that measures the diffuse reflectance spectrum of biological material with single integrating-sphere. The experimental system incorporated a DH-2000 Deuterium Tungsten Halogen Light Sources, USB4000-VIS-NIR Miniature Fiber Optic Spectrometer and an integrating-sphere. Intralipid and ink were used to mimic scattering and absorbing properties of biological material in the tested sample. Total of 30 sample representing of normal and malignant human breast tissue were measured. The measured optical reflectance spectrums with different scattering and absorbing properties were analyzed. The result showed that the diffuse reflectance spectrums of normal and malignant biological material are different in intensity.