Charging high-carbon metallic briquetteHigh-carbon metallic briquette (HCMB) is one option to increase carbon reactivityReactivity in the blast furnaceBlast furnace (BF) upper part. In this research, the influence of carbon levelCarbon level on HCMB reaction behavior in BF was examined. Three high-carbon metallic briquettes (HCMB) samples with different carbon levelsCarbon level were prepared. They were sample A with 24.2 wt.% carbon, sample B with 14.2 wt.% carbon, and sample C with 9.8 wt.% carbon. Isothermal reaction tests were conducted under the simulated BF atmosphere, and the reaction behavior of HCMB under the actual BF environment was performed by theoretical analysis. Results showed that the activation energiesActivation energy of the carbon solution loss reaction of samples A, B, and C were 168.0 kJ·mol−1, 152.5 kJ·mol−1, and 138.1 kJ·mol−1, respectively. In actual BF, the threshold temperatures for samples A, B, and C were 1086 K, 1058 K, and 1026 K, respectively; and their final carbon conversions were 0.25, 0.37, and 0.49, respectively. The research disclosed that the optimum HCMB carbon levelCarbon level for BF application is from 9.8 wt.% to 14.2 wt.%.