A light source module optically coupled to an optical fiber which has a light incident surface is provided. The light source module includes a plurality of light sources and a concentrator. The light sources surround an axis, and the axis passes through a center of the light incident surface and is perpendicular to the light incident surface. Each of the light sources is capable of emitting a beam along a transmitting path toward the axis. The concentrator is disposed at the axis and includes a curvy reflective surface located on the transmitting paths for reflecting the beams to the light incident surface of the optical fiber.