An inspection system and method for inspecting the surface defects of the specimen is provided. The inspection system includes a laser focus module, a microscope objective module, an image pick-up module, and a process module. The laser focus module configured to emit laser beam on the specimen by a predetermined angle relative to a surface of the specimen, and to generate scattered light and reflected light when the laser beam irradiates on the surface defects of the specimen. The process module can calculate the real size of the defects by using the intensity information obtained from the image pick-up module and the microscope objective module or using the diameter information obtained from the reflected light image while the reflected light projects on a screen.