Based on the Mie scattering theory and the low density approximation,anderson localization of GaP photonic crystal is calculated theoretically and the factors are analyzed which influence on the anderson localization parameter.The results show that the photonic crystal of GaP has anderson localization phenomenon in middle infrared with the condition of density of 10% and the ratio of refractive index of larger than 3.8 and without the absorption.With the increase of the particle′s radius,the localization area shifts to long wavelength.And,the increase of medium′s refractive index makes the localization phenomenon weak,which provides theory reference to research anderson localization phenomenon of GaP photonic crystal.