Ozonation is suggested as an effective tool for polymer microstructure characterization. It consists of the selective estimation of the carbon -carbon double bonds content (less than 0.01% mass) and their distribution within polymers. The developed technique consists of measuring the ozone absorbed by the olefin double bonds according to the ozonation reaction. The measurements were carried out by the "Double Bonds Analyzer" (DBA) device. The comparison of the proposed simple and quick method with traditional ones, like GPC, shows good correlation.