Abstract: The emerging technologies of Web services and SOA have supplied a new paradigm for Web application architecture. Because there will be a lot of Web services in the future, which have the similar or same functions, the selection for Web services under group testing has become an ongoing research topic. Based on the related work of Web service selection under group testing, the authors propose a QoS-oriented approach for Web service selection under group testing to overcome the localization of the existing methods, which are only based on function-optimized selection for Web services under group testing. By defining QoS vector, its characters and maximum similar degree, QoS testing oracle, QoS character testing oracles and so on, QoS vectors are clustered by using hierarchical clustering. This approach adjusts the clustering hierarchy dynamically according to maximum similar degree. After the clustering is finished, the selection for Web services under group testing is made by use of QoS testing oracle, QoS character testing oracles and decision tree. It is proved by experiment results that the approach is effective and able to overcome the localization of the existing methods which are only based on function-optimized selection for Web services under group testing.