Mashup is a new application development approach that allows users to aggregate multiple services to create a service for a new purpose. Even if the Mashup approach opens new and broader opportunities for data/service consumers, the development process still requires the users to know not only how to write code using programming languages, but also how to use the different Web APIs from different services. In order to solve this problem, there is increasing effort put into developing tools which are designed to support users with little programming knowledge in Mashup applications development. The objective of this study is to analyze the richnesses and weaknesses of the Mashup tools with respect to the data integration aspect.