In this paper, oxygen precipitates and induced defects in annealed dislocation-free CZ-Si with high oxygen content have been investigated by HVEM. The oxygen precipitates are spherical crystobalite at 750-1050℃. In addition to spherical precipitates, there are some square plate-like oxygen precipitates with {001} habit plane. Punching prismatic dislocation loops are emitted from oxygen precipitates along 〈110〉 directions above 950℃.The loops are interstitial loops with Burgers vector α/2〈110〉 and axis 〈110〉.The loops are generated by a square plate-like precipitate or by a cluster of spherical precipitates. When dislocation loop encounters obstacle, the complex dislocation configuration may be produced. A stage in a stacking fault has been observed, it is formed by climb of the stacking fault. If treatment temperature is below 850℃, no bulk stacking fault results.