Abstract-With the rapid development in science and technology, cloud computing has emerged to be widely adopted in several IT (Information Technology) areas. It allows for the companies as well as researchers to use the computing resources as a service over a network as internet without owning the infrastructure. However, Due to increasing demand of cloud computing, the growing number of tasks affects the system load and performance. Scheduling of multitasks with respect SLA (Service Level Agreement) can face serious challenges. In order to overcome this problem as well as provide better quality of service, the tasks have to be scheduled in optimal way. In this paper, we address the problem of the priority task scheduling through proposing a global strategy over distributed data-center in cloud computing basing on three parameters: tasks deadline, task age and the task length.