The water aerosol fire-extinguishing agent (WAE) is a new generation of Halon replacement. When the fire is taking .place, WAE will rapidly burn and generate a great deal of inert gas, hot mist and a little amount of particulates. After those combustion product are cooled in the cooling layer, they will be discharged into the ambience and extinguish the fire. So, to WAE, the combustion rate has an important effect on the fire extinguishing efficiency. This article mainly discusses the influence law of WAE's compositions on combustion rate.