Exhaust purification device of internal combustion engine

x x x x x x In an internal combustion engine, an NOselective reduction catalyst is arranged in the engine exhaust passage, and a urea aqueous solution feed valve is arranged in the engine exhaust passage upstream of the NOselective reduction catalyst. Based on the detections results of an NOpurification rate detecting means for detecting the NOpurification rate by the NOselective reduction catalyst, a urea aqueous solution feed amount detecting means for detecting the amount of feed of the urea aqueous solution, and a urea aqueous solution concentration detecting means for detecting the concentration of the urea aqueous solution, abnormalities in the NOselective reduction catalyst, urea aqueous solution feed system, and urea aqueous solution are judged.