Conformation is statistical property of the macromolecules consisting of a number of N structural units, links, position of which in a space one relatively to other is not inflexibly fixed by chemical bonds and assumes the possible random configurations. The number of possible configurations at N >> 1 is so great that permits to use the statistical methods at their analysis. That is why the conformation is a result of statistical averaging on all possible configurations of the macromolecule. It was for a long time notified and confirmed by computer modelling that the conformation of polymeric chain should be described by self-avoiding random walks statistics (SARW) but not Gaussian random walks statistics, assuming the phantom behaviour of polymeric chains. Nevertheless, Gaussian statistics is dominating at the analysis of thermodynamic, dynamic and kinetic stainings of the macromolecules conformation. This book will be useful for scientists who are engaged in the physical chemistry of polymers and their solutions.