This paper presents the zone modeling analysis of a single compartment flashover fire. Two criteria are ap- plied in the model to judge the onset of ignition for different combustibles. By calculating the total received energy through radiation or the surface temperature of the combus- tible, the fire growth can be quantitatively determined. The improved zone fire model shows the influence of different combustibles upon the fire growth. This model is better than the traditional zone model because the common criteria of flashover, i.e. an upper layer temperature of 600℃ and the heat radiation intensity received by the floor of 20 kW/m2, have not been applied in it. This paper presents the zone modeling analysis of a single compartment flashover fire. Two criteria are ap- plied in the model to judge the onset of ignition for different combustibles. By calculating the onset of ignition for different combustibles. The fire zone can be quantitatively determined. The improved zone fire model shows the influence of different combustibles upon the fire growth. This model is better than the traditional zone model because of the common criteria of flashover, ie an upper layer temperature of 600 ° C and the heat radiation intensity received by the floor of 20 kW / m2, have not been applied in it.