Grid computing system using dynamic grading and grouping, and data processing method thereof

A grid computing system using dynamic grading and grouping, and a data processing method thereof are provided to allocate/perform a grid computing task by reflecting performance of joining nodes primarily networked to a user node. A resource manager(120) assigns priority to each joining node by using reliability of each joining node according to resource information of each joining node and groups each joining node to a joining group for performing the same sub task. A task manager(130) divides the grid computing task into more than one sub task and requests the sub task to each joining node by each joining group. A resource information storing part(110) stores the resource information of the joining nodes primarily networked to the user node.