The present invention relates to an additional tax refund system in accordance with a dealing using a secured loan and a method thereof and, more specifically, to an additional tax refund system in accordance with a dealing using a secured loan and a method thereof which allow without allowing a seller and a buyer to have a dealing without directly paying an additional tax, through a secured loan or virtual account generation between the national tax service and a bank in the case of the dealing of a real estate product or a movable property.(112) Seller terminal(121) Buyer terminal(200) Additional tax refund server part(300) National Tax Service server part(400) Bank server part(500) Wired and wireless data networkCOPYRIGHT KIPO 2018