Though a constantly increasing number of ontologies are now available on the Internet, the ontology construction process remains generally a manual task, so consequently an effort demanding task. As no unified ontology construction method is available in the literature, researchers started investigating different frameworks for automatically generating ontologies and, therefore shorten the time required for their construction. This master’s thesis presents a prototype system for automatic construction of ontology, based on ontology design patterns and unstructured texts, such as natural language texts. The use of ontology design patterns allow constructing well structured ontologies and reducing the demand of knowledge experts. A difference between our prototype system and the systems presented in the literature is, the possibility to increase accuracy of the generated ontology by selecting the more relevant terms and associations from the unstructured text and match them against the ontology design patterns. Also, a matching score is introduced to define the level of similarity between the terms extracted and the ontology design patterns. By setting a threshold value on the matching score, the relevant ontology design patterns are selected and used for the ontology construction process. The ontology construction framework used by the prototype system has been developed by the research group in Information Engineering of the School of Engineering, Jönköping University.