Kocho-Junisen are considered to have been issued for the purpose of setting Japan's currency system in order by modeling the example of the Kaigen-tsuho of the Tang dynasty of China and also for the purpose of raising funds to cover huge costs required for transferring the national capital to Heijo with margins of profit from the value of currency and the original value of copper material.
律令期に皇朝十二銭が発行された目的としては、唐の開元通宝を手本とし、貨幣制度を整えるため、また、平城京遷都に必要となる莫大な経費を、銅地金本来の価値と貨幣価値との差額で賄うためということが挙げられる。