The trade panel voted in favour that there was a reasonable indication that a US industry was materially damaged by imports of such products, the ITC said in a statement.
The investigations, launched on Jan 23, were aimed at "broadly restricting Chinese exports of silicon photovoltaic products", which had already been hard hit by US anti-dumping duties and anti-subsidy duties on solar cells, a commerce ministry official said requesting anonymity.
The US Department of Commerce is expected to make its preliminary countervailing duty decision in March and its anti-dumping duty determination in June.
The investigations are in response to a petition filed by SolarWorld Industries America Inc. based in Oregon state, which alleged that crystalline silicon photovoltaic products from China were sold below the fair value of the products in the US market, while Chinese producers and exporters also received "improper" government subsidies.
The crystalline silicon photovoltaic products from China under investigation were estimated at $2.1 billion in 2012, according to US official statistics.