Abstract: During the middle and late Kangxi reign, the Qing government reformed the copper administration in order to coin new copper cash. The merchants from the imperial household department as the copper-purchasing contractors, obtained the copper from Japan as much as possible. The reformation achieved success at the early stage, but when the Japanese government set up a new policy to restrict the copper export named“Syoutoku new regulation”in the city Nagasaki, the merchants had to face with a huge deficit and fell into a dilemma. Around how to make up the deficit, Kangxi’s arbitrary decision with the position of partiality to the imperial household department, Showed us a bad example of the powerful emperor’s influence on the Qing government finance.