十六世紀初，明朝政府的財政系統經歷了重大演變。當時，市場的急速發展，使得中央和地方各衙門為了增加收入，陸陸續續將實物和力役稅收折成民間流通的銀塊。這個過程被稱為「一條鞭法」，它歷時頗長，卻相當順利，而其中一個重要的結果，就是促成白銀成為帝國晚期中國政府財政的結算單位。這篇文章要解答的問題是，既然明朝政府在市場發展的路程中，選擇了白銀作為國家財政的結算單位，為什麼又在弘治十六年（1503）開局鑄造銅錢？筆者認為主要原因在於，明代通寶錢的鑄造，與皇帝的私人財政有密切的關係。本文通過分析1503年弘治通寶的鑄造，說明這個觀點。

The current historical literature takes as its starting point the premise that from the Ming dynasty, China made use of a "bimetallic currency." This article investigates why the bimetallic currency emerged in Ming China. In the early sixteenth century, the Ming government experienced tremendous changes in its financial structure. Facing a surge of rapid market development, different levels in the administration, in order to increase their revenues, commuted the land tax into silver payments. This process, called the "Single Whip Reform" at the time, was lengthy but smooth, and produced a significant consequence of the use of the silver tael as the unit of account in government finance. The major question raised in this article, however, is why did the Ming state decide to issue copper coins as an additional currency in 1503? This study, through investigating coinage in the Hongzhi reign, shows a close relationship between coinage and palace expenditures.