Abstract: Mashup has become one of the hottest buzzwords, which is a hallmark of Web2.0 characterized of simplicity, usability, personalization and ease of access. Mashup technology provides a flexible and easy-of-use way for service composition and allows less sophisticated end-users to create customized Web applications. This paper presents the Mashup construction, models and the related technologies, gives overview of current tools, frameworks and patterns that facilitate Mashup development, and then discusses related technical challenges and how they are addressed by research efforts. It finally outlines the new trend of Mashup, especially in the telecom domain.