To provide a two-photon absorption dye-containing material having a great off-resonant two-photon absorption cross section and comprising a two-photon absorption dye capable of decoloring itself through off-resonant two-photon absorption, useful for a three-dimensional refractive index or absorption index modulation material, a three-dimensional optical recording medium, three-dimensional refractive index modulation method and recording and reproducing method for a three-dimensional optical recording medium a two-photon absorption dye-containing material comprising at least a two-photon absorption dye capable of decoloring itself through two-photon absorption.