The rat, which weighed six pounds and had a 12-inch tail, was caught at the weekend in a residential area of Fuzhou, a city of six million people on China's south coast.
He told local Chinese newspapers that he thought the rat might be a valuable specimen, or a rare species, and had to muster up his courage before grabbing its tail and picking it up by the scruff of its neck.
"I did it, I caught a rat the size of a cat!" he shouted out afterwards, according to the reports. Mr Xian is believed to still be in possession of the animal, after stuffing into a bag and departing the scene.