First principles calculations using projector augmented wave potentials and generalized gradient approximations predicts the structural relaxations due to neutral and positively charged oxygen defects (+1 and +2) in bulk thoria leads to symmetric distortion around the vacancy site. Electronic Density of states (DOS) analysis shows presence of defects states mainly contributed by Th d and f states near the conduction band minima for the double positively charged oxygen vacancy which is having lowest energy of formation.