The article makes a brief research on the "Bao" coins of the Salghurids in Fars during the Ilkhanids Period and also makes a comparison with the "Bao" coins found in Xinjiang for the purpose to find out the reasons for minting such kind of coins and in the meantime to expose the cultural significance.

From May to June,2003,a painted tomb of Jin Dynasty is discovered at Yiyang County in Luoyang,in which,some paintings,coins and brown glazed pocelain bowl are unearthed,which provides new materials for studying the ancient painted tomb.

The quality of coins was in disorder in the early years of the Song Dynasty.

Money means the universal equivalent used in history,with marks of fabrication and fixed units,including metal coins and paper money.

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).