This paper investigates the infrared absorption spectra of oxygen-related complexes in silicon crystals irradiated with electron (1.5 MeV) at 360 K. Two groups of samples with low [Oi] = 6.9×1017 cm-3 and high [Oi] = 1.06 ×1018 cm-3 were used. We found that the concentration of the VO pairs have different behaviour to the annealing temperature in different concentration of oxygen specimen, it is hardly changed in the higher concentration of oxygen specimen. It was also found that the concentration of VO2 in lower concentration of oxygen specimen gets to maximum at 450℃ and then dissapears at 500℃, accompanied with the appearing of VO3. For both kinds of specimens, the concentration of VO3 reachs to maximum at 550 ℃ and does not disappear completely at 600℃.