Abstract: The promoter of Anabaena aazollae glnA gene was obtained by PCR procedure.A binary vector containing the chimeric gene of glnA / GUS was constructed after cloning and sequencing.The expression vector was transformed into tobacco by microprojectile bombardment.The GUS activities were examined histochemically in leaves and stems of the transgenic tobacco, but not in its roots.The result was valuable both in the regulation of gene expression, the recognition of transcriptional factors between eukaryota and prokaryota and the construction of practical vectors.