Abstract: Redundant mechanism has been widely applied as an effective means to enhance the reliability of grid systems. However, it will lead to higher ineffective utilization, which in turn brings about many negative effects on applications’ performance. To address this problem, an adaptive redundant reservation strategy is proposed with the aim to mitigate the negative effects of conventional strategies. It provides a mechanism that enables the grid systems adjust redundant degree at runtime without decreasing the reliability. The quantitative relationship between redundant degree and reliability is presented theoretically, and extensive experiments based on real-world workload are conducted to examine the performance of the proposed strategy compared with other redundant strategies. The experimental results show that the proposed redundant strategy outperforms other existing strategies in terms of effective resource utilization. Also it brings about tradeoff between the reliability and the execution performance of applications, which significantly mitigates the negative effectives of conventional redundant strategies.