Geranium L., with about 423 species, is one of the most important genera of the Geraniaceae. In this study, about 67 populations of 10 species of Geranium in Iran were studied in terms of morphology, palynology and anatomy. Data from morphological and pollen studies were analyzed by MVSP 3.1 software. For morphological studies, a total of 58 quantitative and qualitative characteristics were studied in different populations of each species. Pollen samples from each species were examined by light microscopy. For anatomical study, 8 traits were studied in pedicel of different species of Geranium. The studied species were divided into seven groups based on morphological data analysis and three groups based on palynological data analysis. The results of the three types of morphological, palynological and anatomical data showed that in studied species of Geranium, the value of data was different in separating the species. In some species the morphological data and in some others, pollen or anatomical data were effective.