In the national greenhouse gas inventory, the carbon stock in biomass of forests after harvesting has been assumed to release immediately in the year of harvest. Actually the carbon in harvested wood products (HWP) made from harvested forests does not release immediately after harvest, and instead it will decompose gradually in the following years. Some of them can even be conserved in the terrestrial ecosystems if the waste HWP goes into landfill. However, since different accounting approaches may result in quite different results, whether or not carbon stock change in HWP will be included in the estimation and reporting of the land use, land use change and forestry sector in the national greenhouse gas inventory is still pending and has been debating issues in the negotiation of the Conferences of Parties. Many countries have voluntarily estimated and reported the carbon stock in HWP in their national greenhouse gas inventories. In this paper, three approaches (Stock-change, Productions and Atmospheric-flow) and the first order decay method developed by IPCC were applied for estimating the carbon stock changes in HWP of China. The carbon stock changes in HWP resulting from different approaches and data sources (national statistics and FAO data set) are compared and analyzed. The results show that the carbon stock in HWP had been increasing in China since 1900 with an annual mean increase of 2.25×106MgC•a-1 from 1900 to 2003. It was estimated that the carbon stock in HWP of China will be up to 6.14×108MgC in 2020 with the increase of the wood products consumed. The carbon stock in HWP varies with accounting approaches applied. Carbon stock estimated by stock change approach is 2.35×108MgC in 2003, and 0.47×108MgC by atmospheric flow and 1.79×108MgC by production approach. Since China is the largest wood import country, the mean annual carbon stock change in HWP from 1900 to 2020 estimated by stock change approach is 1.17×106MgC more than production approach and 5.66×106MgC more than atmospheric-flow approach. FAO data set resulted in significant larger carbon stock in HWP, compared to China’s data set. Carbon stock in HWP in 2003 estimated using three accounting approaches and FAO data is 2～7 times of China’s data set.