The research community plays a very important role in holding valuable scientific knowledge. The authors propose a community mining system which helps to find communities of researchers by using bibliography data. The key features of our method are a network model of papers and a word assignment technique for the communities obtained. We implemented the proposed method in a graphical computer system. In this paper, we show how research communities are found using our system. Also, we evaluate the performance of the proposed method using experiments with real world data. The results demonstrate that our system can find appropriately sized research communities for a particular scientific field.