The grain purchase funds of national grain depots are usually provided by the government or public institutions, such as the central finance and local governments. These funds are usually obtained through budget, etc., and are used to purchase grain and deposit it in the national grain depot.

In addition, some private enterprises may also participate in the grain purchase of state grain depots, but their sources of funds are usually commercial loans or other forms of financing.

In a word, the grain purchase funds of the national grain depot are mainly provided by the government, and in a few cases, by private enterprises.