Germanates and borates are chemical and structural analogs of silicates. At the same time, there is an essential difference caused by the fact that germanium and boron can have various coordination number depending on structures and temperatures. In germanate and borate glasses a small addition of alkali oxide causes increasing of coordination number of glass-forming cations without breaking of bridging bonds. It is established, that under temperature increasing during a glass-melt transition a reduction of coordination number for a part of glass-forming cations with corresponding depolymerization of anionic groupings and creation of nonbridging oxygens are observed. Under temperature decreasing structures of germanate and borate melts change equally. An increase of a coordination number of glass-forming cations and a formation of a strong network linked through Ge06 and B04 polyhedra take place.