A sub-ontology extracted from its base ontology data contains only the concepts and relationships pertaining to the information required by the user. Sub-ontology extraction and sub-ontology tailoring are then viewed as possible solutions to efficiently utilize large-scale ontology data sparsely distributed on a Semantic Grid environment. This shall contribute to reduce the communication overhead in transporting the ontology data, increase the processing performance, improve the reliability in aggregating the required ontology/sub-ontology, and improve the tailoring process of sub-ontology reuse. This paper discussed preliminary experiments as a showcase to illustrate sub ontology extraction and tailoring on a prototype Semantic Grid environment. Functional analysis and discussion of the results are described.