In order to commercialize the ultrafine-grained material, it is important to understand and improve their thermal stability. Ultrafine-grained materials can be easily transformed into microcrystal line structure because of their low thermo-stability. In this paper, the annealing behavior of ultrafine-grained Ni fabricated by high-pressure torsion (HPT), was investigated by analysing grain growth and texture transformation. X-ray diffraction and orientation imaging microscopy (OIM) were used to analyse texture transformation, microstructure and grain boundary character distribution (GBCD). These investigations demonstrated that grains with a near <112>//ND texture grow abnormally in the initial stage of annealing and the fraction of Sigma3 coincidence site lattice boundaries increased during annealing at 300 degreesC.