AJAX is a popular web-based development model for enhancing application performance and interactivity. Besides enabling web applications to be functional for desktop applications, AJAX is also suitable for calling SOAP web services since it uses an XML based data structure for data exchange. The AJAX based Mash-up service can provide an integrated experience for a user by combining content from various sources. Usually, mash-up consists of a content provider, mash-up server, and a client application. By using AJAX based Mash-up engine, it is possible to easily expand HLA based distributed simulations with different kinds of web services, such as geographic information services, weather information services, and so forth. This paper describes a framework for expanding HLA based distributed simulation with other kinds of web services through the use of AJAX technologies. The proposed framework is a multi-layered architecture which consists of a resource layer, web service layer, mash-up service layer, and application layer. The web service layer wraps resources such as HLA federations, geographic information services in SOAP web services and provides content to the mash-up layer. In the mash-up service layer, content sourced from a federation web services and GIS web services are integrated into new content by an AJAX based Mash-up engine. A user can access and control the HLA federation and GIS service through a browser-based rich client application. By using this framework, HLA based distributed simulation can easily be expanded with different kinds of existing web services, and a more integrated experience can be provided to the user.