In China, a copper coin called Kai Yuan Tong Bao was minted for the first time in the age of the Tang dynasty, and from the age of Northern Sung dynasty, the coin's weight began to be used as a weight unit called 'sen' (in piyin, 'qian').
北宋代以降の中国では、開元通宝という唐代の銭貨の質量が、質量の単位基準として用いられ、それを「銭｣（せん）と呼んだ。