Presentation of results obtained from tests in a diagram is one of the best ways to illustrate laboratory results. Pistachio is one of the most important nuts in the world which has high nutritional and economical values. Iran is the largest pistachio producer in the world and is one of the richest regions regarding pistachio germplasm. Studying genetic diversity is important to protect germplasm storages and also as a prerequisite for breeding. Fourier series can be defined as a function in terms of sin and cosine series. The function can be plotted as a curve in coordinate system. In order to cluster plant genotypes, measured characters of each genotype are replaced with sin and cosine factors of Fourier series so that a function can be determined for it. Plotting all functions in coordinate system and from obtained curves, the genotypes can be clustered. In present study, genetic varieties of some pistachio cultivars in Kerman province have been investigated based on morphological characters. Results obtained from Andrews’ plotted curves were similar with those using Fourier series and cluster analysis. Both classified genotypes in 5 groups. It is concluded that using Fourier series and cluster analysis complement each other and it is recommended that in order to choose cultivars, results of both approaches are applied.