The defects and microstructural evolution of cold-rolled pure zirconium with different deformation reduction were investigated using positron annihilation lifetime (PAL) and transmission electron microscopy (TEM). The results show cold-rolling deformation introduces dislocations and vacancies with high density in the pure zirconium; The mean lifetime increased with increasing amount of deformation up to 10% and then saturated. with increasing cold-rolled reduction. Furthermore, vacancy clusters in the cold-rolled pure zirconium are not formed, and they did not grow even under the isochronal annealing conditions from 298~898 K . The vacancy and dislocation densities of the cold-rolled pure zirconium decrease with increasing the annealing temperature, and they were almost recovery at 873 K.