This paper describes main characteristics of Grid Services based on OGSA and a service component for aggregating service data element. In order to build a Grid Service for SOA, it needs to consider a systematic approach from the high-level software architecture of a system that describes the main system components and their interactions. The purpose of this paper is to design and implement an extended service data aggregator service. To provide reliable aggregating service for service data elements, which is running under wide area environment like Internet, the aggregator service is operated asynchronously by notification mechanism.