18世纪末,鸦片输入中国,通过私贩从东南沿海流入中国内地。1858年中国清政府同英法美三国签订《通商章程善后条约》,鸦片取得合法贸易地位。该条约第五款规定:洋药(鸦片)准其进口,议定每斤纳税银三十两,惟该商止准在口销卖,一经离口,即属中国货,只准华商运入内地,外国商人不得护送。此后输入中国鸦片数量较以前有惊人的增长,导致大量白银外流。1800～1893年输入中国的鸦片数量达63万多箱,价值6亿银 At the end of the eighteenth century, opium was imported into China and inflowed into the hinterland from the southeast coast through private trades. In 1858, the Qing government of China signed the Treaty of Good Deal with the Articles of Association of Britain, France and the United States, and opium gained legal trade status. The fifth paragraph of the treaty states that: "For the import of foreign drugs (opium), it is agreed that the taxpayers will pay thirty-two yuan per catty of taxpayers. Foreign merchants may not escort. Since then, the amount of opium imported into China has increased by a staggering amount than before, resulting in a massive outflow of silver. From 1800 to 1893, the quantity of opium imported into China reached more than 630,000 boxes worth 600 million silver