Abstract: Efficient task scheduling is critical to achieving highperformance on grid computing environment. The task scheduling on gridis studied as optimization problem in this paper. A heuristic taskscheduling algorithm satisfying resources load balancing on gridenvironment is presented. The algorithm schedules tasks by employingmean load based on task predictive execution time as heuristicinformation to obtain an initial scheduling strategy. Then an optimalscheduling strategy is achieved by selecting two machines satisfyingcondition to change their loads via reassigning their tasks under theheuristic of their mean load. Methods of selecting machines and tasksare given in this paper to increase the throughput of the system andreduce the total waiting time. The efficiency of the algorithm isanalyzed and the performance of the proposed algorithm is evaluated viaextensive simulation experiments. Experimental results show that theheuristic algorithm performs significantly to ensure high loadbalancing and achieve an optimal scheduling strategy almost all thetime. Furthermore, results show that our algorithm is high efficient interms of time complexity.