In Korea, the domestic traditional beef named Hanwoo has a large price premium than domestically produced beef made by dairy male cow and imported beef. Therefore, there was a great incentive for dealers in the marketing sectors to deceive the origin of the beef. The introduction of "Law of Labeling the Origin of Beef in Restaurants" makes it difficult to mislabel or deceive the origin of beef traded in the domestic markets. This study investigates the impacts of the law on the Korean Hanwoo market. The results show that the welfare of domestic producers and consumers are improved after executing the law.