In this paper,the characteristics of germanium oxygen deficient cent ers (Ge-ODC) and ring structure in silica fiber materials are analyzed.A Ge-DDC structure characteristics in s ilica fiber materials are analyzed based on density functional theory (DFT) and investigated experimentally using UV-Vis an d Raman spectroscopies.An Si-O-Si structure and a Ge- ODC local model based on three-membered ring (3MR) micro-structure are constru cted.For the free-Ge silica fiber materials,the energy gap is approximately 8.36eV,while for the Ge-doped silica fiber materials,the energy gap is 5.0eV,which will cause a strong absorption center at 242nm corresponding to Ge-ODC.And then the Ge-ODC defect centers have a r elationship between 3MR structure and the Ge atom. After the Ge-doped silica fiber materials are treated by irradiation,the GeE′ and SiE′ defect centers are easily formed.After the silica fiber materials are irradiated by different accumulated doses,the 3MR structures are also obviously reduced with the increase of irradiation doses. In conclusion,the Ge-ODC may be distributed around the ring structure in silic a fiber material,and this local structure is influenced by the external energy easily.It is very important to research the radiation induced d efect in the ultra-lower loss optical fibers.