The purpose of this study is to investigate the reduced scattering coefficient of C6 glioma by the near-infrared (NIR) technique. Light scattering properties of C6 glioma in brain tissue is measured by NIR spectroscopy within the wavelength range from 700 to 850 nm. C6 gliomas were implanted in rats' right brains. The scattering properties of the left and right target corresponding to the position of normal and tumor tissue were measured by a bifurcated needle probe on postoperative days 3, 10, and 17. The results show that there was no significant difference in reduced scattering coefficient between left and right brain tissue at postoperative day 3, but significant decreases were found between left and right brains at postoperative days 10 and 17. This study proved our initial hypothesis that the NIR technique may have a potential for clinical application in brain muglioma diagnosis.