In this paper, we introduce the use of ActionScript 3.0 with web service composition for complex Flash Applications. ActionScript 3.0 is an object-oriented programming language which is used for arithmetic operation and presenting interactive output in Adobe Flash platform. Nevertheless, implementation of all the processes within the flash file itself consume too much of resources in the implementing device. In this paper, we have proposed to use web service composition in ActionScript 3.0 implementation to reduce the development time. Web service composition can provide a flow of system by invoking multiple web services. By using web service composition, we can produce a complex flash application without increasing the size of an independent flash file. Finally, by implementing web service composition in ActionScript 3.0, we can develop a complex web service application with smaller size and portable.