Degenerate primers were designed according to the conserved sequences of NADH dehydrogenase subunit 2 （ND2） gene in mitochondrial tRNAMet and tRNAvrp gene respectively, and the complete sequence of the ND2 gene of Eriocheir japonica was determined. The results indicated that the length of ND2 gene of Eriocheir japonica was 1009 bp. The A, T, G, C contents of the gene were 28.54% （288 bp）, 44.20% （446 bp）, 8.23% （83 bp）, and 19.03% （ 192 bp） respectively; and the sequence was AT rich and biased. The start and stop codons were ATC and A respectively. The homology analysis of nucleotide sequence showed that the similarities in NEE gene between Eriocheir japonica and other crustacean were comparatively low, which suggested that ND2 gene could be effective molecular marker for further study on phylogeny of Eriocheir species.