Cebojiyi district is located in Xainza of Tibet with widely distributed ultrabasic complex, which contains iron ores. Based on field research of geologic feature, the representative samples were selected to analysis the litho-mineragraphic, mineralogic and geochemical characteristics, using microscopy, scanning electron microscope, electron microscope energy spectrum, X-ray diffraction analysis and chemical analysis of powder sample. The results show that ores are dark brown, hard and dense with typical weld-tuff texture, pseudo-flowagestructure and higher relative density; A1-Fe-Mg chromite and wustite are the main crystal minerals, secondary with forsterite, and the mixed crystal minerals fracturing A1-Fe-Mg chromite and Fe-rich chromohercynite are found occasionally with some crystal minerals intergrown by A1- Fe-Mg chromite and wustite; the vitric materials are Ni-rich siallite-ferrite, devitrificated to Ni- Fe-A1 serpentine entirely producing a lot of fine-grain wustite with the primary form; mass fractions of ore SiOz are 13. 59%-20.62% with an average of 16.15%, K, P and Ti are obviously depleted according to the trace element spider diagram, and light rare earth elements are enrich according to the REE pattern, so that the ores are derived from the volcanic Fe-Co-Ni melt from the core but contaminated by mantle and crust ; ore material should come from EM II according to the characteristic of Pb-Sr-Nd isotope; the average mass fractions of TFe2O3, Ni and Co are 53.4%, 6 991×10^-6 and 555×10^- 6 respectively, indicating the ore is Co-Ni-bearing iron ore, which should be focused in prospective evaluation in this region.