OGSA-DAI provides an extensible Web service-based framework that allows data resources to be incorporated into Grid fabrics. The current OGSA-DAI release (OGSA-DAI GT 3.0), published in Sep. 2007, is a complete rewrite of its former version. In this paper we describe the performance of some key components. Under the predefined profiling environment, approach and tools, we conduct profiling from four perspectives: activity and resource performance, data query process performance, database connection and the pressure test. The profiling results would provide guides for the developers to make amendments in their future release, and for users to choose appropriate usages.