Under the constantly evolving requirements from the consumers and competition pressure from the peers, Web Service providers are always striving to improve their services through publishing new versions. As more enterprises chose to embrace SOA, the frequent updates of Web services and increasing distributed environments have resulted in major challenges for all stakeholders to address the evolution of the Web service As a result, lots of solutions have been proposed to deal with the issues caused by Web Service evolution such as models, monitor, analysis, versioning, adaptation, and execution. However, few of them concentrate on the solution that covers all the evolution-related issue under one holistic model which explains 1) what has been changed, 2) when the changes occur, 3) how to apply changes, and 4) how to react to the changes. In this article, we present a change-centric model for Web Service evolution and explain how it deals with the evolution-related issues.