In order to measure the roughness parameters of surface,from analyzing the relationship between the angle distribution of scattering radiance from Gaussian rough surface and the root-mean-square slope of profile,a new measurement for the horizontal profile parameters of rough surface using laser scattering distribution on solid angle was derived.Two values for scattering light features were presented,which are the moments of solid angle distribution of radiance,M(θ) and M（φ）,to represent the laser scattering distribution on solid angle.And the measuring and computing methods were obtained.Experiments proved that the parameters presented can procure the scattering light distribution features on solid angle and can be used for the measurement of the horizontal profile parameters of rough surfaces.