Information visualization based on graph models has many applications in both real and theoretical fields. Since the information that it is desirable to visualize is constantly growing and becoming more complex, more powerful graph-theoretic formalisms are required and appear to represent structured information models with a hierarchical structure. One of these formalisms is the so-called attributed hierarchical graphs. It allows selecting in the original graph a set of such parts (so-called

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... gments) that all elements of each fragment deserve separate joint consideration, and all fragments of the selected set form a nesting hierarchy. Visual Graph is a visualization system which is constructed at the A.P. Ershov Institute of Informatics Systems to explore complex structured big data through their visual representations based on attributed hierarchical graphs. In many applications, objects modeled by graph vertices are complex and contain non-intersecting logical parts (so called ports) through which these objects are in a relationship modeled by arcs. In this paper a formalism of attributed hierarchical graphs with ports and new possibilities of the Visual Graph system for information visualization based on this graph formalism are considered.