The purpose of this research is a specify of interrelationships of various scientific disciplines based on the official declarations of scientists. The most required scientific disciplines was identified for multidisciplinary research. Undirected graphs with the specified parameters was used for modelling of community structure. Based on open database POLON a graph was constructed for the connections among disciplines of science. A number of scientist in particular branches and disciplines of science was presented. As well the connections with in the branches of science and disciplines was shown. Four different measures were considered: percentage of double declarants, vertex degree, weighted vertex degree and betweenness centrality. We found disciplines with highest level of interdisciplinarity, namely: biomedical engineering, informatics, culture and religious sciences, health sciences, and security sciences. In the contrary, very isolated disciplines was found, as following: musical arts, astronomy, visual arts and conservation of cultural heritage, veterinary medicine, and archeology. Finally, we concluded that two of research branches (medicals sciences or management and quality sciences) are the most interdisciplinary in Poland.