Abstract: The results show that the influence of the matrix on the percentage distribution of IO- 4 is small; the oxidation states of 130I found in the cesium chloride are mostly reduction states; the appearance in reduction state for the recoiling atoms formed directly by nuclear reaction is a general phenomenon; the decrease of reduced state in the cesium nitrate matrix is because of oxidation of NO- 2 produced by the irradiation decomposition of nitrate and an obvious unisolated unknown iodine compound.