The TGF-β signaling plays multiple developmental and physiological functions in life. It is important to study the expression pattern of this signal family in vivo. gbb is a homolog gene of bmp7 in Drosophila. In order to study the effect of TGF-β signaling on embryonic development, a polyclonal antibody against Drosophila GBB was prepared. The cDNA sequence of the gbb was cloned (from the library) by cDNA library of Drosophila, and the eukaryotic expression plasmid pCAGGS-P7/gbb was constructed. The BALB/c mice were immunized with DNA immunoassay, and the polyclonal antibody against GBB was prepared by taking serum. The antibody was found to be effective by WB. Through immunofluorescence of Drosophila embryos, it was shown that GBB has no obvious expression at 0~9 h, however, highly expressed signal may be seen after 9 h.