Abstract: The invention provides a light integrating system, which includes a first light source, a second light source, and an integrating rod thereon defining an axial direction. The integrating rod includes a transmitting surface and a reflecting surface disposed beside the transmitting surface. There is an angle between the normal direction of the reflecting surface and the axial direction. The transmitting surface is substantially perpendicular to the axial direction. A first light emitted by the first light source passes through the transmitting surface into the integrating rod. A second light emitted by the second light source passes through a side surface of the integrating rod and is reflected by the reflecting surface into the integrating rod. The integrating rod mixes the first light and the second light reflected by the reflecting surface in the integrating rod and transmits them out.