In this paper an approach in realization of analogy-based reasoning in semantic networks is presented. New semantic model, called Active Semantic Model (ASM), was used. Core of the process is performed by ASM’s association (semantic relation) plexus upgrading procedure based on recognition and determining similarity between association plexuses. Determining similarity between association plexuses is performed by recognition of topological analogy between association plexuses. ASM responds to unpredicted input by upgrading new association plexus modeled on remainder of the context whose subset is recognized as topologically analogous association plexus.