Abstract: An automated optical inspection system for the runout tolerance of circular saw blades comprises a rotating device, a first and a second optical inspection module, and a computing device. The rotating device is used to rotate a circular saw blade. The circular saw blade includes multiple teeth, and each tooth has a side and a back. The first/second optical inspection module is used to capture a side/back image of the tooth. The computing device activates the rotating device to rotate the circular saw blade, and activates the first and the second optical inspection module to capture the side image and the back image of each tooth upon rotation of the circular saw blade. The computing device performs a radial-position-calculating procedure according to the side images, to obtain an amount of radial runout, and performs an axial-position-calculating procedure according to the back images, to obtain an amount of axial runout.