A fundamental concern in building a secure grid computing environment is authentication of local and remote entities in the environment. The existed authentication technologies in the grid computing environments can effectively guarantee the valid authentication, but they cannot meet the demands of new security challenges in dynamic grid environment, such as flexibility, lightweight, and extensibility. In order to satisfy the security needs of the computational grid, we propose a reflective authentication framework which aims to improve the customizing ability of platform and adaptive ability in the open and dynamic grid environment.