<p>Promoters are considered valuable tools for biotechnology and provide great opportunities for eugenic purposes. This study aimed to investigate the expression pattern of GUS gene directed by CaMV 35S promoter in transgenic rapeseed (<em>Brassica napus </em>L.). The GUS gene was transferred to the rapeseed explants by <em>Agrobacterium</em>. The regenerated and rooted transgenic plantlets were transferred to the pots containing a mixture of soli and vermiculite. These plants underwent PCR and histochemical GUS assay. The cross-section of leaf, petiole, and stem of the transformed plants was obtained. GUS activity was observed in phloem, parenchyma, collenchyma, and supporting tissue of vascular bundles. It was also observed in cambium, endoderm, vascular ray, pith parenchyma, epidermis, and trichomes. These results showed that CaMV 35S causes the expression of transgene in various tissues differently.</p>