The study aims to identify the measurement bases of accounts Assets and Liabilities evidenced in the Explanatory Notes in 2006 and 2010 of the largest publicly traded Brazilian companies listed in the Revista Exame - Melhores e Maiores de 2011. The descriptive study in a purposive sample of 30 companies used the application of content analysis to categorize the data needed for the inferences and Correspondence Analysis (ANACOR) to involve the disclosure of the measurement bases of assets, and liability from 2006 to 2010. The results shown with the χ2 test showed that the items accounting Financial Investments, Stocks and Investment showed no significant difference, having no changes in their measurement bases. The Current Cost prevailed for Financial Applications, Cost History and realizable value for inventories and the Equity Method for Investments, even though this is a method of accounting and not based on measurement of assets. Other accounts differ significantly between the bases of measurement, and the concept of the fair value as a vector of the changes from one period to another. It is concluded that the companies have significantly changed the basis of measurement of the accounts of active and passive from 2006 to 2010, despite the short time of revision of the law nº 6.404/1976.