Optical limiter is the protective device of optical system,the protec tive characteristic of it is caused by the optical nonlinear effects related wit h light intensity or power of the light-limiting material,and photo-induced s ca ttering in photorefractive crystal is one of these effects,which has attracted worldwide attention for many years.For this kind of photo-induced scattering, s ome researchers proposed that it is caused by the surface and volume scattering of crystals,and the experiments were performed with LiNbO₃:Fe,LiTaO₃,and BaT iO₃,crystals at fixed distances between focusing lenses and samples.In order t o further explore the generation mechanism of the scattering,the characteristics of the light-induced anistropic scattering under laser irradiation in KNbO₃: Fe crystal are experimentally investigated.The light-induced refractive index cha n ges in KNbO₃:Fe crystals have been measured by Z-scan technique.Meanwhile,the optical limiting properties of light scattering in crystals have been studied.T he results show that the scattering from KNbO₃:Fe crystal is mainly due to the l ight-induced lensing.The optical limiter using light scattering effect in phot o refractive crystal,can be adjusted by changing the crystal size,lens focal len gth,small aperture size and so on.Meanwhile,because it work with low power co ntinuous wave laser,it can withstand higher power and longer life.