In this work it is shown how the PB (Poisson Bracket) for different physical systems can be obtained proceeding from transformation that leave invariant the kinematic part of the action. Outside integral terms in the action variation are interpreted as generators of these transformations. Equations for determination of the admitable variations are found. On the base of developed approach we have considered the classical continuum, the theory of elasticity, hydrodynamics, the number of liquid crystal phases as well as the magnetically ordering and superfluid systems. (author). 18 refs.