In computer and information sciences, an ontology is, in its essence, a named set of axioms encoding a network of relationships and dependencies between ontological entities present in a knowledge domain. With the rise of Semantic Web technologies, real-world ontologies have become considerably large leading to complex ontology networks. In this chapter we firstly present an overview of previous research works dealing with analysis of ontology networks. Nodes of ontology networks can be enriched with various metrics reflecting complexity and quality attributes of corresponding ontological entities. On a case study involving one large-scale modularized ontology, we demonstrate that analysis of enriched ontology networks can help ontology engineers not only to understand the structural complexity of ontologies, but also to evaluate their quality with respect to well-established modular design principles.