The effect of HPC (Hyper-coal), which was affected by the iron oxide, on coal particle adhesion during carbonization was investigated. X-ray diffraction analyses were carried out to obtain changes of iron oxide crystal structure on HPC with iron oxide addition during caking temperature. The promoted weight loss of HPC by the iron oxide during caking temperature was calculated from the weight losses by thermogravimetric analyses and gas concentrations by a gas chromatograph and a Karl Fischer titrator. Furthermore, to reveal the effect of iron oxide on coal particle adhesion at resolidification temperature, the yields of semi-coke with and without HPC/High Fluidity-HPC (HF-HPC)/Fe2O3/Fe3O4 were measured, the strength of the semi-coke samples was evaluated using diametral compression tests, and the adhesion of coal particles was evaluated using microstructure analyses. As a result, the promoted weight loss of HPC was increased by the catalysis of Fe2O3, and was decreased, when the Fe2O3 was reduced to Fe3O4, due to hydrogen atoms in the thermoplastic components of HPC. Thus, the strength of semi-coke with HPC increased. Furthermore, although the iron oxide affected the HPC, the adhesiveness of coal particles, which was an index of ferro-coke strength, was enhanced by HPC, and the adhesiveness of HF-HPC was higher than that of HPC. Therefore, the HPC decreased the chemical effect of iron oxide, and improved the adhesiveness.