In this study, from the material properties of the aggregates into the actual applications were evaluated for utilizingthe air-cooled blast furnace slag as the coarse aggregates (SG) in PHC piles. The physical and chemical characters ofthe SG were satisfied the standards presented in KS F 2544 for concrete blast furnace slag aggregates. And it was satisfiedthe environmental-factor-evaluation, including the soluble, heavy metal elution and total mercury content, and etc. In casethe non-washed type SG is used, the S/A ratio adjustment according to micro-powder of the aggregate surface and chemicaladmixture adjustment are needed in order to satisfy the aimed material properties. As the replacement ratio of SGincreased, the manifestation rate of compressive strength of the PHC piles was decreased. Particularly, in case non-washingtype SG, the manifestation rate more decreased. Therefore, the elimination of the pop-out materials and cleaning processare necessary for the production process for using the SG as coarse aggregates of PHC Piles