We are developing a bubble-projection three-dimensional display (BP3DD) that will generate reflecting points in a liquid. This type of display is currently nonexistent. In this paper, we examined bubble generation in water and ethanol to find the most suitable conditions for the BP3DD. Experimental results showed that when the water pressure was lower, the required energy to generate bubbles decreased linearly. The required energy should be lowest when the water pressure is similar to the water vapor pressure. When bubbles were generated in ethanol solution, the required energy was lower than that required in water. The minimum required energy to generate bubbles was approximately 2 J. We can conclude that the required energy to generate bubbles is dependent on the physical properties of the liquid and its pressure.