A specific spectrometer system with mini-invasion fiber probe was used to obtain the optical parameters of brain tissue within C6 gliomarbearing rats in vivo and real time,and demonstrate the feasi-bility of using optical parameters to identify tumor and help clinical diagnosis. The optical parameters of C6 glioma tissue and normal brain tissue were measured by the specific system. Reducing scattering coefficient(μ＇_s)and oxygen saturation(SO₂)were recorded in vivo for C6 glioma-bearing rats' brain tissues and normal brain tissue. The experiment results show that μ＇_s and SO₂ can display some valuable information,such as the location and pathology grade of C6 glioma. μ＇_s and SO₂ measured by near infrared spectroscopy can beused for glioma quantification and lay the foundation for clinical application.