Effects of boron concentration upon oxygen precipitation were studied in Czochralski (CZ) silicon annealed from 2 to 128 h between 450 and 1050°C. In this ivestigation Bragg line profile (BLP), high resolution diffuse X-ray scattering (DXS) and transmission electron microscopy (TEM) were employed. The BLP and DXS data have shown that the nature of the predominant deffects depend upon annealing time and temperature, as well as, on dopant concentration. The long range displacement field of these defects, however, does not seem to be affected by these parameters. The TEM results have shown a dependence of precipitate growth kinetics, as well as, structure upon dopant concentration, and annealing temperature and time. Differences in oxide precipitate growth kinetics between lightly and heavily doped materials and a correlation between DXS parameters and TEM images are discussed. © 1987.