It is shown that description of composite systems can not be depleted by the corrections to known equations of state and dynamics of mechanical systems. In particular, poor there is description equilibrium of such systems on the basis one function, increasing in time — entropy, and equal measure of chaos. Within the framework of a new initial postulate about statistical equilibrium, founded on entroduction of entropy, characteristic of clutter, and characteristic of the order, it is possible to present some integrated approach to the description of regularities of composite systems.