Inflammable characteristic produces an inevitable challenge for the corn storage, which endangers the food demand of human being. We investigated the combustion behavior evolvement of corn under different heat flux, with the aid of cone calorimeter. The reciprocals of square rooted time to ignition presented a linear relation to heat flux (y = 0.0036(q + 11.0833), R-2 = 0.8944), similar to other materials. Higher peak values of heat release rate were obtained in heat fluxes of 20 kW/m(2) and 25 kW/m(2), due to longer heat time and moderate heat flux. Total heat release value was decreased only when heat flux was low to 10 kW/m(2) and presented a significant decrease in heat flux of 5 kW/m(2) (decreased to 39.0 MJ/m(2) from 63.0 MJ/m(2)). It also found that the ignition temperature for the corn combustion was near 365 degrees C; meanwhile, the surface temperature of corn combustion was higher with higher heat flux. As the XPS analysis presented, the main elements of combustion residue under 35 kW/m(2) were C 1s, O 1s, Ca 2p, K 2p, B 1s, and Si 2s. Results from Raman spectra and XRD curves indicated that the graphitization degree of combustion residue was gradually decreased with increase of heat flux.