The goal of grid networks is to integrate all of hardware and software capabilities of the different sets of computers as a comprehensive system, in order to calculate andprocess the data. Data has play key role in Grid computing. Support of distributed resources and prevent any unauthorizedaccess to data, require a secure access control system to gridnetwork. In this article with use of OTP security mechanism by workflow, we present a new strong authentication method forlogging to grid systems for controlling allowed access to grid networks for increasing security, to envelope all of security services such confidentiality, collectivity, identification and as Non-repudiation and prevent any security threats.