Much like other processing domains, cloud computing is not surely safe. Security of cloud processing needs the same attention as any other aspect of cloud processing requires. Cyber world is shifting toward ontological technique and web 3.0 or web semantics for security. Cloud hosts servers demand more attention in context of security as number of resources and their access increases. Security measures have to be more extensive in cloud. Semantic web is usually new revolution inside the web science, which usually works upon base of ontologies. Ontologies are receiving great attention in the domain of computing and hence in the domain of security. This review paper examines different proposed “ontology centered techniques” and also provides a comprehensive analysis on these tactics. This research paper gives critical analysis of different models presented by different authors and researchers for ensuring security of a cloud based environment. This analysis helps different vendors of cloud technology to adapt one or all of these models to practically implement in their cloud machines whether they are offering IaaS, PaaS or SaaS. Any new security model using ontologies can also be proposed based on this study, as this paper gives a comprehensive comparison of the previously proposed ontologies for monitoring security state of cloud environment as safe or malicious.