Disassembly, as one of the core steps in the End of Life (EOL) activities, has been a popular topic of research in both industrial and academic areas. It not only reduces product lifecycle cost, but also substantially influences environmental impact. Although different methods have been proposed for tackling different aspects of the disassembly planning problems, certain gaps still exist. For example, in the case of the disassembly sequencing, traditional methods focus mainly on the geometry and topology constraints, but omit the important technical constraints like force (gravity), connector type, etc.; it makes these methods less efficient and realistic. Also, the determination of an optimal disassembly sequence requires an extensive exchange and sharing of the disassembly related knowledge among the different stakeholders like manufacturers, product designers, maintenance staffs and material engineers. A mechanism to support such information interoperability is important in the disassembly process. In order to address those research issues, this paper proposes a Semantic Web based Disassembly Planning Framework. In the framework, the proposed "Disassembly Core Ontology" (DCO) serves as a formal, explicit information core for different users like product designer and disassembler. By exploiting the rich semantic knowledge (like gravity, connector type, etc.) that has been explicitly embedded in the proposed DCO, it has been demonstrated that the semantic web approach has potentials to address both efficiency-and interoperability-related issues in disassembly planning problems.