To in silico clone the NAD1 gene of three common parasites and analyze their bioinformatics, so as to lay the foundation for further research on the NAD gene.By using the in silico cloning method, the full length cDNA (s) of NAD 1 genes of Clonorchis sinensis, Ascaris lumbricoides and Schistosoma japonicum were got, then their physical and chemical properties, compositions of amino acids, subcellular localizations, binary and ternary structures were contrastively analyzed.The three kinds of NAD1 proteins were similar in the relative molecular weight, subcellular localization, and physical and chemical properties. The NAD1 proteins were highly similar in binary and ternary structures of A. lumbricoides and S. japonicum. The phylogenetic analysis showed that C. sinensis, A. lumbricoides and S. japonicum belonged to the different evolutionary branches with a certain of genetic distance.The three NAD1 genes got from C. sinensis, A. lumbricoides and S. japonicum by in silico cloning belong to the same gene of different species, which can be widely used in the researches of heritable variation of parasites.