Dihydrolipoamide dehydrogenase (DLDH) is a multifunctional oxidoreductase and is well known as an essential component of four mammalian mitochondrial multienzyme complexes: pyruvatedehydrogenase, α-ketoglutarate dehydrogenase, branched-chain α-keto acid dehydrogenase, and the glycine cleavage system. In the previous study, we described the cloning, purification, and oxidoreductase activity of recombinant silkworm, Bombyx mori DLDH (BmDLDH) expressed in Escherichia coli. In the present work, the result showed that 1) BmDLDH was present in both mitochondria and cytoplasm, but BmDLDH in mitochondria was more abundant than that in cytoplasm, which indicated the BmDLDH could be dual localized. 2) Both the expression levels and diaphorase activity of BmDLDH in silkworm first instars and moth were higher than those in other development stages. The transcript levels of BmDLDH were not different in developmental stages. 3) The transcription, expression, and activity of BmDLDH in Malpighian tubule were higher than those in other tissues.