Ontology plays an important role in the enhancement performance of systems, addressing issues such as knowledge sharing, knowledge aggregation as well as information retrieval and question answering. This paper presents the AGROVOC Concept Server Workbench (ACSW) for multilingual ontological concept construction and maintenance. The ACSW is a web 2.0 based application consisting of two main functionalities that are user management and ontological knowledge management (i.e. concept, scheme, relationship, export, search, validate and consistency check) in order to maintain the knowledge acquisition life-cycle in food and agriculture domain. Knowledge is stored in the form of multilingual concept hierarchy and also kept in the OWL format in order to exchange between machines and to do reasoning. This workbench uses Protégé API as an OWL framework. Moreover the Ontology Game conceptual framework is also presented in order to acquire ontology terms more pleasant.