【摘要】This paper briefly surveys the literature of measures of trade openness and points out the main factors affected the size of trade openness. Then we estimate the trade intensity in China and adjust it after several selected factors.The conclusion is that the nominal trade intensity in China has been larger than its theoretical value, especially for 2001～2003. Reasons for the deviation of 2001～2003 are (1) the lag effect of the accession into WTO; (2) the depreciation of USD and (3) other trade policy and industry policy.