The thesis summarizes the key concepts of software testing and reviews the base of acceptance testing and testing based on Specification By Example. It delineates the theory and the technical solution of the testing by the help of Concordion. It shows the installing and using of the SBE based Concordion system through examples and tutorials. Concordion is able to test service oriented architecture applications, for which testing is fundamental for security reasons, too. The thesis describes the RESTful web service determinated by the consultant to test and its configured environment for testing. Creating a sample system, which can support the testing of SOA applications, is also the goal of the thesis. To execute the testing of the web service it defines the examined test cases and gives the SBE description for using of Concordion. It includes the related client programs written in Java language. It describes the steps of the testing of the web service by the help of Concordion, then rates the results of the testing and makes a proposal for the eventual modifications of the system. Finally it summarizes the experiences in the testing and analyses the opportunities to define how to improve the system.