Bioinformatics is becoming increasingly important as an interdisciplinary science. One of its most important contributions is to sequence the genomes of living organisms and the illustration of evolutionary processes. The phylogeny is one of its major applications, which tries to understand the evolution of the species. After a molecular biological analysis, the collected data is analysed by a clustering algorithm and drawn as a phylogenetic tree. This bachelor thesis is about implementing such a clustering Method in Java. From a given distance matrix of organisms a family tree is calculated by the UPGMA algorithm and displayed visually on the screen. The way the program is designed allows the implementation of extensions if needed.