Objective To establish a model of acute gouty arthritis( AGA) in rats and observe its maintenance time. Methods The AGA model of rats was established by injecting monosodium urate ( MSU) at the concentration of 25 mg/mL into the ankle joint cavity. The rats were observed for 8 d at different time points. Skin temperature, degree of joint swelling, gait, inflammatory cells in synovial fluid, histopathological changes of synovial tissue and other indicators were observed to determine whether the modeling and maintenance time were successful. Results At 3 h after modeling, differ-ences in the swelling of ankle joint, increase of skin temperature, abnormal gait, the number of inflammatory cells in syno-vial fluid, synovial hyperplasia, capillary congestion, and disarrangement of synovial cells in the rats were observed in the saline group and the model group (P <0. 01). At 4 hours after modeling, the above mentioned inflammatory changes in the saline group were significantly reduced, compared with that at 3 h, showing a significant difference (P<0. 01), while the inflammatory changes of the model group were increased significantly compared with that at 3 hours ( P<0. 01 ) , and showed significant difference compared with the saline group (P<0. 01). At 24 h after modeling, the indexes in the rats of saline group returned to normal, but the inflammation of the model group was increased. At 48-72 h after modeling, the local inflammation such as ankle swelling, skin temperature, and abnormal gait of the rats in the model group reached a peak. The inflammation of the ankle joint in the model group was gradually reduced from 96 to 168 h after the model was established, but there were still significant differences in the indexes compared with the blank group (P<0. 01). At 192 h after modeling, the joint swelling, skin temperature and abnormal gait of the rats in the model group returned to normal, however, there were significant differences in the number of inflammatory cells and the pathological changes of synovial membrane compared with the blank group ( P<0. 01 ) . Conclusions A rat model of AGA can be successfully prepared and identified at 4 h after modeling by injection of MSU crystal suspension into the ankle joint cavity. This rat model of AGA can be maintained at least 168 hours after modeling.