The monetary systems with local characteristics，known as market currency ( money that circulated in a particular market ) systems，were gradually formed in regional markets in the Qing dynasty．An economic area，whose market currency was decimalized，came into existence in the Qingdynasty．The economic area was centered at Fengtian Province，and it spread to adjacent territories，such as Zhili，Inner Mongolia and Jilin．This article focuses on decimal currency and analyzes its emergence and evolution in Fengtian．The price ratios between decimal currency and market currency，between decimal currency and silver after Qianlong period，are systematically unraveled for the first time．The author conjectures that money notes issued by various stores supported the dynamism of the monetary market of market currency．Such unofficial notes were circulated in accordance with the monetary system．Ultimately，market currency formed a huge paper money market，which existed until the end of Qing dynasty．