The modern concept of polymers is similar as covalently bonded macromolecular structures. The theory of phantom networks was developed in the forties by James and Goth. The network is composed of cross-linked Gaussian chains. It is assumed that there are two types’ network junctions. There are various theories of phantom networks. The more detailed analysis of the phantom network is given by the following theories; James and Guth theory, affine models of rubber elasticity of Wall and Flory and Edwards’s replica and tube theories.