Abstract: The breakage ratio in stranding process of 00. 22 mm steel tire cord cold-drawn from 05. 5 mm coil produced both process flow sheet of 70 t BOF-LF-①380 mm bloom CC-breakdown 150 mm x 150 mm billet-CR and 200 t BOF- LF-200 mm x 200 mm bloom CC-CR process is ①380 mm round bloom process-2. 86 times/t and 200 mm x 200 mm bloom process-less than 1 time/t. Examination results show that the main factor for massive cord breakage is distinct central segregation of coil produced by round bloom, and the macro carbon segregation of 150 mm x 150 mm rolled billet is up to 1. 1 L Using bloom casting flow sheet with cross section size more than 200 mm x 200 mm, control over heating degree of liquid in tundish 15-25 °C, constant casting speed and using mold and end electromagnetic stirring are available to decrease the central segregation.