In today's changing economy managers of the leading companies understand that the key sources for value creation are Intangible Assets (IA). The latest surveys confirm the fact that nowadays these assets are the value drivers and not "traditional" assets having tangible form. The same surveys confirm the fact, that one third of all the effected investment solutions is based on the existing Intangible Assets, and that the decisions made on the basis of IA allow them to make a more accurate prediction of income and profitability of a company in the future, and, hence, the company's value for the shareholders. The research held in the paper defines the impact of fundamental value of both tangible and intangible assets on the market value of assets of Russian companies. As a general approach used herein for IA evaluation, the method of Calculated Intangible Value (CIV) offered by T. Stewart was chosen. According to CIV the evaluation of Intangible Assets is based on residual operating income (REOI) model as a variant fundamental value of equity model. The problem of Intangible Assets composition and structure is also covered in the paper. Developed econometric models are tested on the data of Russian stock market for two periods: from 2001 to 2005 year and from 2001 to 2006. In the focus of the research there is both the analysis of the sampled companies (43 companies) as a whole as well as divided into five aggregated fields: mechanical engineering, extractive industry, power engineering, communication services, and metallurgy. At the end of the paper the authors highlight the main directions for further research in the field.