This article aims to analyze the decline of 'Tai-yun' circulation structure. 'Tai-yun' refers to the transport of rice, collected as land tax in Taiwan, to Qing troops and their families stationed in Fukien. By comparing the difference in rice price between Taiwan and Quan-zhou Prefecture, as well as that in various parts of Taiwan, this article examines the role played by rice price in 'Tai-yun' and its transformation. During the 18th century, rice in Taiwan was inexpensive. Merchants from China took advantage of the price difference and engaged in exports of rice from Taiwan. Such trade exchange was allowed by the Qing government because the merchants' vessels helped undertake the official duty of 'Tai-yun'. The circulation structure of 'Tai-yun' was dependent on commercial vesselss for rice transport while subjected to restrictions under government policies concerning official ports, navigation routes and vessels allowed. After the end of Lin Shuangwen Rebellion, the rice price of southern Taiwan rose (1788-1789 A.D.), and exceeded that of Quan-zhou Prefecture, meaning diminished profits for rice exports from southern Taiwan. The relatively lower rice price of northern Taiwan drove merchants to export rice from illegal ports in the central and northern Taiwan. At the same time, to shun their commitment in 'Tai-yun', rice merchants began to transport rice in fishing vessels and small boats, which were not allowed to cross the Taiwan Strait. Such intentional evasion of 'Tai-yun' persisted throughout the reign of Emperor Jiaqing (1796-1819 A.D.), during which the price of rice all over Taiwan dropped. Profits from rice trade continued to decline in the mid 1830s when the difference in rice price between Taiwan and Quan-zhou Prefecture further narrowed. Hence, reduction in profits led to fewer merchant vessels visiting official ports for rice trade, thus affecting 'Tai-yun' declined by the decrease of commercial fleets. Consequently, the circulation structure of 'Taiyun' disintegrated during the first half of the 19th .