The structures of Arctic shelf include a number of large sedimentary basins, connected with prospective utility of oil and gas bearing capacity (for example, South Barents, South Kara, South Laptev and North Chukchi depressions). Creation of Earth's crust models of shelf basins requires more data about petrophysical parameters of rock. Using the available seismogeological data, and taking into account the potential fields data, the 2D and 3D density models of Earth's crust have been constructed for water areas of Russian Arctic seas for more than two decades. During the creation of models, there was carried out the petrophysical analysis, as a result of which, there were obtained the data, characterizing the changes of density parameters of the Earth's crust. Results of researches can be used at joint processing and interpretation of data of seismic exploration and potential fields, which is necessary for increasing of reliability of received sections and specification of structural borders. In the absence of drilling operations in the region, the density parameters of main seismic stratigraphy horizons, received as a result of model calculations, are irreplaceable during the prediction of collecting properties of sedimentary cover and development of models of hydrocarbonic systems formation.