Stress-activated protein kinase in rice (OsSAPKs) plays an important role in signal transduction. In this study, we analyzed the function of OsSAPK9 in response to Al stress in rice. The results indicated that absorptive capacity for aluminum in the roots of OsSAPK9 over-expressing transgenic rice was significantly lower than that of non-transgenic plants at 6?h, 2?d, 6?d and 10d after 10?mmol/L Al stress. Compared with the wild control, the reduction percent of plant height of OsSAPK9 over-expressing transgenic plants was significantly lower than that in non-transgenic plants 20?d after treatment using 10?mmol/L Al. Moreover, the activities of Superoxide Dismutase (SOD) and Peroxidase (POD) in the roots of OsSAPK9 over-expressing transgenic plants were higher than that in non-transgenic plants. While, the activities of SOD, POD and Catalase (CAT) in the parts above root of overexpression transgenic plants lower than that in non-transgenic plants. These results indicate that OsSAPK9 might be involved in the regulation of tolerant resistance response to Al stress in rice.