"Charity granaries" (yicang 義倉) were local granaries founded on the initative of wealthy members of the society who thus donated part of their wealth to the public welfare. In some places charity granaries were run on the base of special taxes levied for this purpose. The oldest evidence for privately organized granaries dates from before the Sui period 隋 (581-618) in the short-lived state of Northern Qi 北齊 (550-577). At that time each family delivered an annual tenancy (kenzu 墾租) of 2 shi 石 of grain and a donation of 5 dou 斗 for the charity granaries (see weights and measures).
Emperor Wen 隋文帝 (r. 581-604) of the Sui dynasty adopted this system in 585. Minister of Revenue (duzhi shangshu 度支尚書) Zhangsun Ping 長孫平 suggested that everyone might donate part of his income to the commonly founded local granary. The authorities thus retained part of the taxes to stock this granary. The charity granaries, although inspired by the central government, were run by local personnel, and has thus a semi-official status. They were first operated in districs on private initiative, but then also founded in prefectures, where the local government took over the organization. It was regulated that rich households would donate one shi of grain, middle-income ones 7 dou (or 0.7 shi), and households with lower incomes 0.4 shi.
The Tang dynasty 唐 (618-907) ordered in 628 the each member of the nobility (i.e. bearers of the titles of wang 王 "king" and gong 公 "duke") were to donate 2 sheng 升 per mu 畝 of land, to serve as grain for the charity granaries. In 651 the rule was expanded to each hosehold. The amount of grain to be delivered depended on the income, with a ceiling rate of 5 shi of grain. In 739 a new method was introduced, according to which each household was classified in a "green-sprout booklet" (qinmiao bu 青苗簿) and delivered an amount of 2 sheng of grain (rice, wheat, millet) per mu of land to the local charity granary. Special regulations fixed the reduction of this quota in years of bad harvest.
Merchants, who did not own or work fields, contributed a certain amount of grain according to their income, ranging between 5 dou and 5 shi. The smaller charity granaries supplemented the larger system of ever-normal granaries (changpingcang 常平倉) that was founded in the early Tang period. In combination the system was called changping yicang 常平義倉, at least in the early decades of the 9th century. Not all dynasties followed the same organizational methods.
The Song dynasty 宋 (960-1279) required a tax of 1 dou of grain per shi of tax, while those of a harvest of lower than 1 shi were exempted from the "charity tenancy" (yizu 義租). The Southern Song 南宋 (1127-1279) increased these fees by a donation of various types of silk fabric (yijuan 義絹, yichou 義綢). In 1186 the great Neo-Confucian philosopher Zhu Xi 朱熹, in whose home district Chong'an 崇安 a crop failure had occurred, donated the huge amount of 600 shi to the local granary. In 1181 he suggested to the central government to expand the system of local granaries, and submitted to the throne some proposal for the organization of this system. It would be organized by a a member of the local gentry (xiangshen 鄉紳) who relied on the support of the district magistrate. Local granaries and the prefectural ever-normal granaries mutually lend grain in case of need. Granaries were also allowed to give credit, at an interest rate of 2 dou per shi of rice (20 per cent). Emperor Xiaozong 宋孝宗 (r. 1162-1189) accepted the proposal and ordered this kind of mutual assistance to be realized in the empire.
The Yuan dynasty required a payment of 5 dou of grain for free persons (qinding 親丁) and 2 dou per serf (quding 驅丁).
During the Ming period 明 (1368-1644), the charity granaries were privately organized. Twenty or thirty households were forming one "community" (she 社), with a community head (sheshou 社首), a community leader (shezheng 社正), and a vice leader (shefu 社副), who were organizing the collection of grain for the community granary, according to three different ranks of income. Apart from the quota, each household paid a loss surcharge (sunhao 損耗, see haoxian 耗羨) of 5 he 合.
The Qing dynasty 清 (1644-1911) again subjected the system to public supervision, while the organization was left to the local communities. In 1729 an imperial decree even forbade official interference into the system.
The term yicang was only fixed in 1679 when the Kangxi Emperor 康熙 (r. 1661-1722) defined that yicang were granaries in cities, while those in smaller, more rural communities were called shecang. Yet the names xiangcang 鄉倉 or juncang 郡倉 were also common for the latter. In the organization of these two types, there was no great difference. Granaries in prefectures were called changpingcang, and these were differently organized.
In the second half of the nineteenth century the system of charity granaries more and more disintegrated, as it was heavily effected by the destructions during the Taiping rebellion 太平起義.