A method and system to measure and image the full optical scattering properties by inverse spectroscopic optical coherence tomography (ISOCT) is disclosed. Tissue is modeled as a medium with continuous refractive index (RI) fluctuation and such a fluctuation is described by the RI correlation functions. By measuring optical quantities of tissue (including the scattering power of the OCT spectrum, the reflection albedo α defined as the ratio or scattering coefficient μs, and the back-scattering coefficient μb), the RI correlation function can be inversely deduced and the full set of optical scattering properties can be obtained.