The article analyses the reasons of the prevalence of private coins-making and the deficiency of copper coins in Tang dynasty in terms of the characteristics of making copper coins.

In order to control the appreciation of copper coins in the market, the government of Qing Dynasty adopted measures as follows: 1) increasing the amount of copper coins; 2) increasing the supply of the key material of coinage, that is, copper; 3) dealing with the problems of adversely affecting the circulation of coins, such as illegal coinage and making copper instruments by melting coins.

This paper explores the fluctuation and its major causes in the exchanging rate between two metallic urrencies---silver and copper coin during the Ming & Qing Dynasties(1368-1911).

Study on Extraction of Flavonoids from Hydrocotyle sibthorpioides var.;