By adopting the RCA, CMS, TCD, SI and TCI models, this paper has made an empirical analysis of the comparative advantages and complementarity of the agricultural trade between China and the United States in terms of sixteen major agricultural products since 1997. The results indicate that (1) the exporting agri-products of China and the United States reflect the characteristics of the resource endowment of each country; (2) China's agri-product competitiveness has decreased after its WTO accession, while the country's agri-export structure has been upgraded; (3) Sino-US agri-trade dependency continues to rise, and the U.S. relies more on China than China does on the U.S.; (4) China and the United Sates have good complementarity in the agricultural trade, which tends to strengthen after the China's accession to the WTO. Policy implications are proposed accordingly based on these findings.