A chimney structure of vessel is provided to reduce installing and maintaining costs by installing an air injection unit in an exhaust pipe for improving exhaust efficiency. A chimney structure of vessel includes an exhaust pipe(10) and an air injection unit. The exhaust pipe is installed on the vessel for exhausting exhaust gas generated while driving an engine. The air injection unit includes a pump(20), an air passage(30), and a nozzle(40). The pump generates air pressure to pass through the air passage to the nozzle. The air passage connects the pump and the nozzle for transferring the air pressure up to the nozzle. The nozzle injects air pressure into the exhaust pipe to increase in an exhaust speed of the exhaust gas for reducing contamination of the vessel.
