Since China's entry into the WTO, US anti-dumping (AD) actions against China have increased, particularly with respect to multiple petitions. Distinguishing between US single and multiple petitions, we examine the trade effects of US AD actions against China based on an unbalanced panel of quarterly trade data. The results show that a US single petition investigation greatly restrains US imports of the filed products from China but also causes more significant import diversion from non-named countries. In the short run, a preliminary AD duty imposed on China via a US multiple petition not only restrains US imports of the filed products from China but also prevents trade diversion from non-named countries. In the long run, a final AD duty on China resulting from a US multiple petition creates a larger destructive effect on China and causes US import diversion from non-named countries. Thus, a final AD duty imposed on China following a US multiple petition not only harms China's exports but also fails to help the US achieve import substitution. Furthermore, we have been able to reveal the negative trade effect of a preliminary AD duty even in cases where the ultimate decision is not to impose a final duty.