This study discribes characteristics of water spray for extinguishment of gasoline pool fire. Experiments are carried out for the gasoline pool fire in a small tank with a diameter of 150mm and a height of 8mm. Droplet size, spray pressure, amount of water which reaches the flame base and velocity of water spray are measured to find extinguishment conditions and air entrainment due to the water spray is visualized. Critical conditions of water spray for extinguishment of gasoline pool fire is quantitatively shown.