In Grid environment, with a view to allocate and manage Grid resources, on-line schedulers aim at meeting all kinds of uses’ resources requests, rather than paying enough attention to resources providers. In order to increase resources providers’ profit and encourage sites to provide service actively, a cost-computing based task scheduling scheme is proposed, which calculates sunk cost and opportunity cost, based on relative information provided by users, to decide whether to accept the task, such that both resource providers and customers will achieve their economic goals, therefore, to promote the development of whole market more stably. Experiment shows that the scheduler reduces the cost of resources providers，increases their profit, and effectively encourages sites to offer more resources.