Herein it has been made an attempt to find some mathematical models of the main laws of psychology on the basis of the variational principle of the subjective entropy maximum. On the basis of the subjective entropy of an individual preferences extremization principle, using the necessary conditions for extremums of a functional to exist, we get the widely known main fundamental laws of psychophysics: the Bouguer-Weber, Weber-Fechner, Stevens, Zabrodin laws. It has been considered a few special cases of the models for the aggregating functions for sensations and perceptions, as well as cognitive functions for preferences and desires. Also it was obtained expressions for canonical distributions in the case of two-dimensional distribution of sensations and perceptions. The proposed approach, postulating the extremality of human's psych functioning, has the theoretically substantiated value for researches with the use of the principle for the general empirical laws in applied psychology.