China\'s Ministry of Commerce said Thursday that it will impose provisional anti-dumping duties on imported solar-grade polysilicon from the United States and the Republic of Korea. Starting July 24, Chinese importers of solar-grade polysilicon from the United States will be required to pay deposit rates with Chinese customs ranging from 53.3 percent to 57 percent, depending on the dumping margin, the MOC said in a statement posted on its website. Importers from the ROK will have to pay deposit rates ranging from 2.4 percent to 48.7 percent, according to the statement. \"After preliminary investigations, we found exporters in the United States and the ROK dumped their products on the Chinese market and caused material harm to China\'s domestic solar industry,\" the MOC said. Last October, the U.S. government imposed anti-dumping and countervailing duties on crystalline silicon photovoltaic cells from China. The commerce department said Chinese producers and exporters sold solar cells in the U.S. market at dumping margins ranging from 18.32 percent to 249.96 percent, and they received countervailable subsidies of 14.78 percent to 15.97 percent. Solar-grade polysilicon is an important material for making solar cells.