Abstract: Dependent task scheduling problem in mobile grid environment is studied and dynamic scheduling strategy is presented which includes pre-scheduling and re-scheduling.Pre-scheduling maps all tasks to currently available resources using modified HEFT algorithm,with goal of shortest completion time,taking into account the energy constraint of resources.During the running of tasks,resources will be monitored.If resource behavior is abnormal and meets rescheduling conditions,then re-scheduling is triggered to achieve adaption to dynamic environment. Experiment results show the effectiveness of presented scheduling strategy.