The surface ripple modality of Si/Ge material 1 06 μm laser-induced is measured by optical microscope. It indicates that the subsequent laser will cause positive feedback to increase the ripple after the appearance of laser-induced materials' initial ripple. When power density of laser beam is close to damage threshold, periodical ripple will present on surface of the material; and when the density exceeds damage threshold, stochastic distribution will appear in melting area of the material. The surface ripple modalities occur on Si and Ge materials whose characteristics are dependent on the material property, surface status. At the same time, the infections of the surface ripple structures are analyzed for the laser beam propagation characteristics and the damage effects of laser beam interactions with materials.