Executing the legacy program over grid is very important and necessary. To reuse the legacy program, we developed a method based on Component for executing the legacy code. We can deploy the legacy program as a Component without re-engineering the code, or even requiring access to the source files. This approach is based on the Grid Component Model (GCM). In this paper, we describe the GCM and the model of the legacy program Component including the Legacy Program Interface Description, the File Transfer Mechanism, the Adopter and the Execution Management. Then it introduces the implement of this model and presents the performance evaluation through the example of Bioinformatics. The experiments demonstrate that it has the better performance and provides the characters of reliability, interoperability and flexibility.