清代早期顺治、康熙、雍正朝铜钱,多铜质精好,铸制规整,厚重大型,自乾隆朝始,因铜价上升,制钱成本加大,制钱的质量逐渐下降,铜质渐劣,钱型减小。咸丰年间学者唐与昆编《制钱通考》载:乾隆初年,按雍正十一年定制钱式,每文铸重一钱二分,乾隆三年又改铸一钱,乾隆五年又改铸七分, The early Qing Dynasty Shunzhi, Kangxi, Yongzheng copper coins, fine copper, cast regular, large and heavy, since the Qianlong Dynasty, due to rising prices of copper, money costs increase, the quality of money gradually declined, the deterioration of copper The money type is reduced. In the early years of Emperor Qianlong, according to the custom of Yongzheng for eleven years, each piece of paper cast a piece of money and one piece of paper for two years, Qianlong once again cast a piece of money for three years, Cast seven points,