The storage of carbon in harvested wood products (HWP) is an important forestry issue in the United Nations Framework on Climate Change Convention. Given that China is a large HWP-trading country, studies on carbon storage and flow of HWP trade are important to help mitigate carbon concentrations in this country. Total carbon storage has continuously increased, and the accumulated carbon storage of HWP in use is greater than that from wood harvested in China. The average annual changes in carbon stock from 1961 to 2011 based on stock-change, production, and atmospheric-flow approaches were 10.6, 7.6, and 2.6 Mt C per year, respectively. Carbon flow in wood product imports has increased constantly, thereby increasing carbon stocks via a stock-change approach. Based on atmospheric-flow approach, large imports of primary wood materials increased the carbon emissions. As a result, the trade of HWP has made HWP in China become a “carbon source.”