The relathionshiops between industry attribution and knowledge management-A case study on Petroleum and Petro-chemical Industries, steel industries, and TFT-LCD industries. To meet the demands of the market and create demands and hence to build up new competitive advantages in the knowledge-economy world, the focus of enterprises is to manipulate knowledge, make good use of the characteristics of knowledge-sharing and innovation. Therefore, knowledge management can be deemed as a weapon for organizational management and organizational development. With fine-quality knowledge, enterprises can create new knowledge and enhance corporate competitiveness. The aim of this research is to explore the differences of the mechanisms of knowledge management and the relationships between industry attributions and knowledgement among enterprises. With interviews with companies and relevant literature review, we conclude the following researching findings: Research finding 1: When the technologies in an industry go into a ripe phase, the model of knowledgement tends to focus on integrating explicit knowledge; when the technologies are still in the growth phase, the model of knowledge management focuses on internal interaction. Research finding2: Enterprises place more importance on knowledge transfer and their knowledge management mechanisms focus on information system when the industry life cycle is in the ripe phase; enterprises value knowledge innovation and their knowledge management mechanisms focus on the platform of human interaction when the industry life cycle is in the growth phase. Research finding 3: Industries in ripe phase emphasize the knowledge storage, diffusion, and application; industries in growth phase emphasize the knowledge creation. Keyword: knowledge management, industry attribution, industry life cycle, mechanism of knowledge management.