Abstract: A broadband gonioreflectometer for light scattering measurement is introduced, and a method of broadband bi-direction reflectance distribution function(BRDF) measurement is proposed. The gonioreflectometer incorporates a broadband white light source and a broadband detector with a diffraction grating and linear diode array, obtaining 400~700nm BRDF measurements with a relative measurement method. The finished instrument is capable of combining wide angular coverage over the incidence/reflection hemisphere, dense sampling of the visible wavelength spectrum, and rapid operation. To prove the usability of the system, measured BRDFs on two samples are reported.