Engineering Internet Commerce is about building Web-enabled enterprise information systems to carry out business transactions over the Internet. This engineering task is related to three aspects: the requirement specification, the Internet technology, and the development methodology. In the requirement specification, the business analysis and design is conducted to create a semantic business model that will reflect both the business and the system requirement. With the Internet technology, the modern information technology infrastructure is investigated in order to transform a business model into an implementation model. The system analysis and design will be performed and the architecture issues should be discussed. With respect to the development methodology, an efficient way to build enterprise information systems is addressed. This chapter is to provide an overview of the problems, concerns, and the background in an effort to rationalize the Internet Commerce Engineering.