Updated project metadata. The development of the testis involves a large number of tissue-specific proteins, possibly because that sperms in it are the most divergent of all cell types. Although the proteome of the larval testis of Bombyx mori has been reported, no comprehensive data on adult testis proteome is available for silkworm. In this study, Liquid chromatography-tandem mass spectrometry was employ to investigate the protein compositions of the adult testis of silkworm. A total of 14431 peptides were identified in the adult testis of B. mori, which were match to 2292 proteins. Thirty-two heat shock proteins constitute a group of most abundant proteins in the adult testis, suggested that they are critical for the development, differentiation and survival of germ cells. Other proteins in this analysis were also involved in testis-specific processes mainly including sperm motility, meiosis, germ cell development, and spermatogenesis.