IN RECENT YEARS, COMPLEXITY OF SOFTWARE DESIGN HAS INCREASED IN THE SOFTWARE DEVELOPMENT PROCESS (SDP) AND ITS PLAYS AN ESSENTIAL ROLE IN SDP. TIME AND COST ARE THE MAJOR FACTORS THAT DECIDE THE QUALITY OF THE SOFTWARE. UML CLASS DIAGRAM REUSE CONCEPT USED TO REUSE MODEL IN THE DESIGN PHASE. IN ORDER TO RETRIEVE THE INFORMATION CORRECTLY, THIS STUDY HAS APPLIED ONTOLOGY-BASED RETRIEVAL TECHNIQUE USING SEMANTIC SIMILARITY CONCEPT. RETRIEVAL CAN BE ACHIEVED BY MEASURING THE SIMILARITY BETWEEN UML CLASS DIAGRAMS. IN BRIEF, THE INTENTION OF THIS APPROACH IS TO CONSIDER THE UML CLASS DIAGRAM AS A QUERY, AND IT IS REFORMULATED USING QUERY EXPANSION BY DOMAIN ONTOLOGY. QUERY IS USED AS A SEARCH PATTERN INSIDE THE KNOWLEDGEBASE, IN WHICH UML CLASS DIAGRAMS ARE INDEXED FOR IMPROVING THE SEARCHING PROCESS. ITS ELEMENTS ARE ANALYZED BY APPLICATION ONTOLOGY. DURING THE RETRIEVAL PROCESS, VARIABILITY BETWEEN TWO CONCEPTS IS REDUCED BY, DIVIDE BY MAXIMUM TECHNIQUE. FINALLY, THE EXPERIMENTAL RESULTS ARE RANKED FOR DESIGNHER SELECTION.