[en] The possibility of determining the boron content in polymer materials has been studied with the aid of the neutron-absorption method. The method is based on measuring the density of the flux of heat neutrons with the energy of 0.025 eV passing through the sample under study. The time of analyzing boron in polymer materials, including the preparation stage, is 10 minutes. It is expedient to perform the analysis in the concentration range of 0.1-O.3 weight % of boron, since the determination error in this case meets the production requirements. The concentration range may be broadened using a source with a higher neutron yield, detector with a larger recording efficiency, and cuvette with a complex-shaped geometry