A device for purifying exhaust gas may be provided to purify exhaust gas in an engine includes an exhaust line through which exhaust gas discharged from the engine passes, a diesel oxidation catalyst (DOC) that is disposed in the exhaust line to purify hydrocarbon (HC) and carbon monoxide (CO) of the exhaust gas, a urea injector that injects a urea aqueous solution into the exhaust line, and a selective catalyst reduction (SCR) that reduces nitrogen oxide of the exhaust gas passing through the DOC by use of the urea aqueous solution, in which the DOC includes an LTA zeolite catalyst.
