Blowout experiments of methane-air diffusion flame by using a water vapor vortex ring have been performed. The water vapor vortex ring was produced by a single droplet impact onto a heated flat plate. The blowout probability was measured. The process of water droplet impact on the heated wall was observed by using a high speed camera. The boiling behavior and condition to generate the vortex ring were clarified. It was found that the wall temperature at 250℃ was the most effective condition for the flame extinguishment.