Most developed Si-N containing oligomers and polymers are silazaneorganic oligomers and polymers - one of the applicable siliconorganic poly-functional compounds with inorganic-organic main chains. They are using for production of various important technical compositions and materials with specific properties: polymer varnishes and coatings, water-repellents, polymer ceramics and silicon-nitride fibers, etc. They also successfully used in nanotechnology and as modifiers of the other organic and elementorganic oligomers, polymers and materials on their basis. In this book are described practically important and technologically justified four methods for obtaining polyfunctional siliconorganic polymers with organic - inorganic main chains.