[en] Highlights: • Radiation levels of flue gas from an integrated steel plant in China were measured. • These findings constitute the first report on stack releases of radionuclides in China. • Sintering was the main process that released natural radionuclides. • ²²²Rn, ²¹⁰Pb and ²¹⁰Po were the main radionuclides released into the atmosphere. - Abstract: Crude steel production in China made up the majority of the global output, at 49.5% in 2014. High temperature smelting processes result in the release of natural radionuclides, including radon gas and other air pollutants into the atmosphere. This paper conducts an analysis of the raw materials, end products and flue gas sampled from an integrated steel plant from within China's Jiangxi Province, with annual production of 8.50 Mt of crude steel. Normalized stack emissions factors of radionuclides from steel production were first reported in China. The results showed that sintering was the main process that released natural radionuclides, and the main radionuclides released into the atmosphere were ²²²Rn (86.4 GBq/Mt), ²¹⁰Pb (13.4 GBq/Mt), and ²¹⁰Po (1.71 GBq/Mt). The results provided essential basic data for radiological impact assessment of steel production, as well as that of nuclear energy chain, coal chain and other electricity sources.