In providing the infrastructure for the accomplishment of general purpose computational grids the main concern is security. Still, by properly authenticating users and hosts and in the interactions between them, most grid implementations focus their safety concerns. The effective and competent exploitation of grid computing services needs sophisticated and secured resource management systems. The wide range of selection and the high degree of strangeness leads to the problem in secured selection of grid. Without the assurance of a higher degree of confidence relationship, efficient resource allocation and utilization can not be attained. In recent times, with larger applications in e-commerce reputation mechanisms have become one of the most important techniques underpinning the distributed application and system safety. We have proposed a new approach in this paper, which intends to offer trust and reputation aware security for resource selection in grid computing. Based on the calculated trust factor (TF) value of each entity the incoming jobs have securely allocated to the entity.