Abstract: Grid resource allocation is one of the key problems to grid computing.More and more grid researchers are paying attention to the problem of grid resource allocation.The process of grid resource allocation is the maps processes of the tasks and resources.Based on the analysis of the existent grid resource allocation methods，this paper has bring forward an agent-based approach for grid resource management，which is divided into five layers：user layer，costumer service layer，information service layer，area administer layer，resource layer.Based on this，agent coalition mechanism for resource allocation in the grid is analyzed.At last，an example of the model is given.