A direct-type reflective diffusion lens and a lighting installation including the reflective diffusion lens. The reflective diffusion lens includes a first reflective surface concave and having a longitudinal cross-section with a parabola shape or normal distribution shape to totally reflect incident light, and a bottom surface comprising a light incident surface concave toward the first reflective surface. The reflective diffusion lens includes a second reflective surface having a longitudinal cross-section inclined by a first angle with respect to a central axis of the lens to totally reflect incident light and a refractive surface connecting the first reflective surface with the bottom surface. The refractive surface includes a first refractive surface having a longitudinal cross-section inclined by a second angle with respect to the central axis and a second refractive surface having a longitudinal cross-section inclined by a third angle with respect to the central axis.