The paper is devoted to the analysis of custom tariff formation process during Russian WTO accession. The authors analyze what factors were the main determinants of inter-indu­stry differences for the Russian WTO import tariff lines. Specifically it is tested whether the industry output, industry import and price elasticity of demand for import were the main determining factors for the industry tariff rates after the transition period of Russian accession. Also, the authors analyze the sensitivity change of import tariffs to the main determinants subject to industry lobbying. The deep theoretical review of economic models analyzing the tariff formation process is observed to form the appropriate model, different econometric methods such as ordinary least squares and the method of instrumental variables is used to test the hypotheses. The empirical study of Grossman – Helpman model leads the authors to the conclusion that inter-industry differences in import tariffs cannot be fully explained by the industry lobbying, industry output and price elasticity of demand for import. The Grossman – Helpman model hypotheses are valid only for certain industries, and subject to very specific assumptions for industry lobbying – for all industries in sample. The main paper result is that on average lobbying industries (ceteris paribus) managed to gain higher tariff protection levels after transition period of Russian WTO accession.