In order to test the tissue expression pattern of endosomal AtNHX6 gene, we amplified the promoter sequence of AtNHX6 gene from Arabidopsis thaliana, a 1 922 bp upstream of reading frame (ORF) by PCR. The fusion expression vector pCAMBIA1381proNHX6GUS was successfully constructed by the AtNHX6 gene promoter and GUS gene and introduced into the A. thaliana (ecotype Columbia 0) by the floral dip procedure. The homozygous T₃ transgenic A. thaliana lines was identified by PCR amplification of a 2 187 bp fragment. The expression pattern was monitored using GUS histochemical staining. The results showed that GUS staining was preferentially observed in cotyledons, hypocotyls and flowers of transgenic seedlings carrying the AtNHX6 promoter. In these organs, the highest GUS activity was detected in the vasculature, although GUS was widely expressed. In true leaves, GUS activity was only partially detected for the AtNHX6 promoter. In the root, GUS was expressed in the root hair and lateral root growth site. In immature siliques, GUS staining was restricted to the silique tip and base for the AtNHX6 promoter, but was detected only in fruit stalks in mature siliques. In flowers, GUS staining was observed in the filament of the stamens and pollen grains within the anthers and the ovarian stigma for the AtNHX6 promoter. Results from histochemical GUS assay suggested that fusion expression vector of AtNHX6 gene promoter and GUS was successfully constructed and it drives the expression of GUS gene successfully. The results also showed that AtNHX6 gene predominantly expressed in vascular tissues of cotyledons, hypocotyls, roots, flowers and siliques and the growth site of root hair and lateral root, as well as filaments, pollen, ovarian stigma of A. thaliana.