Section 301 Tariffs. Throughout 2018, the Trump Administration imposed four tranches of tariffs, known as Lists 1, 2, 3, and 4a, on imports from China. His administration found this authority in Section 301 of the Trade Act of 1974, which allows the president to impose tariffs on imports from countries that engage in unfair trade practices.
https://www.americanactionforum.org/research/section-301-china-tariffs-by-end-use/

