This present research applied the ATR-FTIR technique and principle component analysis (PCA) to investigate molecular surface changes in the pre-carbonized solid biomass, so call Kindai Bio-coke and Japanese cedar which is utilized as an alternative to coal coke in the cupola furnace of the steel industry in order to reduce the CO 2 emissions. The aim is to explore what can be the key to improve the BIC products applications from the fundamental molecular scale by using PCA to distinguish between changes during the BIC transformation and the differences in BIC samples. Results revealed that transformation occured at the surface of Japanese cedar raw materials and Japanese cedar BIC. Major changes were observed in the O-H, C-H and CO stretching regions. The intensity of the IR bands attribute to aliphatic methyl (CH 3) and methylene (CH 2) stretching modes increased while a weak O-H stretching intensity associated with BIC hydrophobic characteristic decreased.