Bluetongue virus (BTV) infection of ruminants is endemic throughout much of the US and China. The S10 and a portion of the L2 gene segments of Chinese prototype strains of BTV serotypes 1, 2, 3, 4, 12, 15, and 16 were sequenced and compared to the same genes of prototype and field strains of BTV from the US. Phylogenetic analysis of the S10 gene segregated the Chinese viruses into a monophyletic group distinct from the US viruses, whereas similar analysis of the L2 gene segregated strains of BTV according to serotype, regardless of geographic origin.