Genetic assessment of invasive plant species that adapt themselves and propagate in many regions in the world is important for the further study to avoid ambiguity. The variations of many parts of invasive plants called phenotypic plasticity are affected by regional effects of its invaded place such as climatic and geographical traits. It is important to make it clear whether the variations of the plant parts are derived from the regional traits or genetic differences. The aim of this study was to assess the genetic distances of the invasive species, Ulex europaeus from the four different regions such as Maui, California, Hawaii and New Zealand prior to the further studies. As Ulex europaeus is an allohexaploid species, which often shows genotypic ambiguity by normal single nucleotide polymorphism (SNP), microsatellite method was used for the assessment because it has been used frequently to test the genetic distances of the hexaploid plant species these days. We tested the leaf samples of 37 mother trees from four regions (11 from Maui, four from California, seven from Hawaii, 15 from New Zealand) at five microsatellite loci. After polymerase chain reaction analyses (PCR), dinucleotide-repeat motifs (DRMs) were counted and compared to test the genetic distances of the samples. As a result, dendrogram and analysis of molecular variance (AMOVA) showed that Ulex europaeus sampled in four different regions were genetically very close.