The most prominent feature of liquid atomization depends on prompt and huge transfers from kinetic energy to surface energy. In flight of a lumps of liquid with free surface condition, liquid deforms its surface area according to the increasing order of ratios of various characteristic forms to the initial complete spherical or cubic forms. Thus, we give reasons why there are three susceptible forms such as sheet or membrane with, so called, many wave lengths, ligaments and/or annuli, and spherical drops.
We suggest that the theory for liquid discharge might be constructed on the basis of the maximum principle of conditional entropy. Various atomization processes of liquids could widely discussed by using this simple entropy. The response stability of mechanisms of liquid disintegration under steady condition has to be discussed by this entropy. It also point out that there are many problems remained to study further.