The catalysis of K₂CO₃ on the reactivity of top charged coke and stamp charged coke from Pansteel in China was studied. The coke reaction index of the stamp charged coke was 1%–2% higher than that of the top charged coke. Under the catalysis of K₂CO₃, the coke reaction index of both cokes approximately increased by 4%, 6%, 10% and 6% at 900, 1000, 1100 and 1200℃, respectively. The reactivity of the K-enriched stamp charged coke was 1%–2% higher than that of the K-enriched top charged coke below 1100℃. However, only negligible differences were found in the temperature zone between 1100 and 1200℃. Scanning electron microscopy images illustrated that pores in the top charged coke were smaller and equally distributed, while relatively more big pores exist non-homogenously in stamp charged coke. Due to the different processes in production, the stamp charged coke was more porous and most of the pores tended to be applanate. Cracks were observed in the microstructure of the stamp charged coke during the carbon solution reaction, implying the inferior quality of the stamp charged coke to the top charged coke at high temperature. Diffusion of K during the carbon solution reaction was studied by the energy dispersive spectrometry. It is found that K gradually spreads into the center of lumpy coke with the rising of temperature and is equally distributed on the edges of pores at 1200℃. Besides, oxidation reactions of functional groups become faster with the catalysis of K.content