China's commerce ministry will start an anti-dumping investigation into steel products imported from South Korea, Japan, the European Union and Indonesia.
Beijing will look into stainless steel billets, or bars, as well as hot-rolled plates from the four countries.
The probe is at the request of a Chinese steel firm, which claimed such products accounted for more than half of the domestic market from 2014 to 2017.
The ministry plans to carry out surveys, check samples, hold public hearings and conduct on-site inspections to determine if the imports truly are hurting the local industry.