Using positron lifetime and Doppler broadening lineshape parameter measurements, the recovery behaviors of defects in the deformed and post-deformation hydrogen-charged poly-crystalline pure Co have been studied. Experimental results indicate that the cathodic hydrogen-charging of deformed sample further introduce an additional amount of dislocations and vacancies as well as some vacancy clusters into it. However, it appears that mirrovoids and microcracks are not produced. The recovery temperature range of vacancies is 73-260℃; the annealing of dislocations and vacancy clusters occur in the range of 350-670℃. The migration activation energy of vacancy was measured to be 1.09±0.07eV.