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.