The conditions for decolorization of apple dietary fiber were established for laboratory study.The microwave method was applied to the optimal conditions for decolorization of apple dietary fiber.In this study,the optimal conditions determined by response surface methodology(RSM) were: pH 12.5、microwave time 47.75s and H2O2 concentration 9.17%,material-solution ratio 1∶ 14 and microwave power 480W.Under the above conditions,the Whiteness was 57.34%(mean value) in the final product,while 27.54% before the decolorization.The effect was significant.The empirical model developed by response surface methodology(RSM) is adequate to describe the relationships between the factors and response value.The results of the curve by scanning electron and X-ray diffraction analysis showed that microstructure of the apple dietary fiber surface was changed by microwave.