Homeotic genes are important for the regulation of the developmental processes. We have examined the regulation of the expression for ultrabithorax gene, which is a kind of, homcotic genes of Drosophila melanogaster in the embryogenesis at anterior part of the embryo. We have already known through the transgenic Drosophila melanogaster that transcription factor GAGA, which binds to proximal promoter from -200 bp to -31 bp, cross-talks with upstream cis-regulatory elements. We will map the upstream regulatory elements of the ultrabithorax gene which cross-talk with GAGA transcription factor. To study this, we have made the plasmid constructs which bind to proximal promoter containing GAGA binding site, and various deletions in 22 kb upstream sequence; pCpW β-Xkb- GAGA -ubx- LacZ- P-element plasmids (GAGA 1.2 kb, GAGA 6.1 kb, GAGA XhoI-XhoI religated). Microinjecting them into embryos of Drosophila melanogaster, we have analysed the anterior part of embryos with β-gal assay. The results were: GAGA 1.2 kb and GAGA 6.1 kb didn`t show the suppression of the expression for ultrabithorax gene at the anterior part of the embryo, but GAGA XhoI-XhoI religated site did. Therefore we supposed that the regulatory site may be in the GAGA XhoI-XhoI religated site which lacks -19 kb to -12 kb of total 22 kb upstream sequence.