Internal cracking surrounding primary carbides in high carbon steel as-cast blooms induced by soft reduction is investigated to elucidate their influence of internal cracking on carbide precipitation and the resulting segregated band in hot-rolled wire rods. The primary carbides precipitation in high carbon steel has been investigated using both experimental observations and finite element simulations for as-cast blooms induced by soft reduction. It is found that the carbides precipitation in the vicinity of existing internal cracks is often located midway between the surface and centreline of the bloom, further increases the occurrence of the segregated bands in the hot-rolled wire rods. In addition, the growth of primary carbides surrounding the internal cracking are based on the chemical driving force and high density precipitate zones have been clarified in continuous casting bloom induced by soft reduction. It clearly shows that the spatial distribution of internal cracking surrounding primary carbides that play a key role in the formation of the segregated bands in the final steel products.