Background <p>Trichomes play important roles in improving plant environmental adaptation. Potato (<i>Solanum tuberosum</i> L.) leaves have a dense distribution of trichomes, divided into two major categories: non-glandular trichomes (NGTs) and glandular trichomes (GTs). However, the ultrastructural features and GT secretion have not been adequately studied. This step of research is crucial in revealing the role of trichomes in defense.</p> Methods <p>We analyzed the ultrastructural characteristics of potato trichomes using transmission microscopy and the localization of GT metabolites using histochemical staining.</p> Results <p>The results show that different types of potato trichomes have specific ultrastructural features: NGTs consist mainly of basal and stalk cells and have little internal cytoplasm, primarily large vacuoles, and thicker cuticles. GTs consist mainly of basal cells, stalk cells, and glandular head cells. Furthermore, the head cells of GTs exhibit dense cytoplasm. Glandular head cells have abundant organelles, such as mitochondria, chloroplasts, endoplasmic reticula, Golgi apparatus, and nucleus. Golgi apparatus multiple membrane sacs and active metabolism, generate numerous osmiophilic vesicles that migrate toward the cell wall, rupture, and release osmiophilic material. This material is stored in the space between the cell wall and the cuticle, and secreted from GT head cells when accumulated in excess. Histochemical staining of trichomes revealed that GTs secrete a variety of substances, and developing GT head cells accumulate secondary metabolites, such as phenolics, alkaloids, terpenoids, and flavonoids, while small quantities of these secondary metabolites are distributed in type VI glandular neck cells.</p> Conclusions <p>NGT constituent cells lack organelles and secretory function and depend on thickened cuticles to remain upright and stiff. The organelles in GT head cells allow for active cellular metabolism, such as the synthesis of secondary metabolites like phenols and alkaloids. These findings, along with those of other plants of the genus <i>Solanum</i> (tomato), suggest that GTs may play important roles in potato leaf chemical defense. Overall, the type, structure, and secondary metabolite composition of potato trichomes demonstrate their constitutive defense functions and warrant further research. These phenotypes could provide additional options for breeding insect- and disease-resistant cultivars.</p>