This research was carried out with the aim of introducing, identifying and evaluating the morphology and phenology of species present in the Iranian National Botanical Garden. Initially, the display area of 1.8 hectares was divided into six sections. Their planting plan was prepared and species were identified. Then, phenological changes were reviewed over 20 years. The results showed that 63 tree species, 87 species of shrubs, 31 species of grasses and 14 species of plantation crops, overally 195 species and cultivars of 100 genera and 45 families, were located in the experimental plot and adapted to the climate of Tehran. Then, the phenological changes and their uses in forest or green space were studied to determine six groups such as: most longitudinal and diagonal growth per year (16 species), relatively stable (12 species), evergreen (33 species), species with changes in leaf color (6 species), long flowering period (10 species), and autumn or winter flowering (5 species).