Information integration has become a critical challenge during power deregulation due to many significant issues such as how to efficiently manage and incorporate the information sources that are independently distributed nationwide and how to make the information integration system more reusable, flexible and adaptive to changing market rules. To meet the above challenges, a new software architecture is proposed based on the concept of semantic ontology, where information sources are integrated into a semantic knowledge warehouse (SKW). A semantic reasoning software component (SRSC) is developed accordingly to automatically deduct new information from SKW. Such a software architecture is very suitable for the information integration in power market. Furthermore, the concept of deduction credibility is proposed to further refine the reasoning process in SRSC.