In this paper we discuss a novel framework for policy based scheduling in resource allocation of grid computing. The framework has several features. First, the scheduling strategy can control the request assignment to grid resources by adjusting resource usage accounts or request priorities. Second, Efficient resource usage management is achieved by assigning usage quotas to intended users. Third, the scheduling method supports reservation based grid resource allocation. Fourth, Quality of Service (QOS) feature allows special privileges to various classes of requests, users, groups, etc. This framework is incorporated as part of the SPHINX scheduling system that is currently under development at University of Florida. Experimental results are provided to demonstrate the usefulness of the framework.