In addition to the sources of funds for production and operation, enterprises also have special sources of funds formed by specific sources. According to the accounting system, the sources of special funds in China can be divided into: ① internal formation of enterprises. Special funds are mainly formed within the enterprise. Part of it is extracted from the cost, including employee welfare fund, major repair fund and renovation fund; The other part is formed by the retained profits of enterprises, including production development funds, incentive funds, welfare funds and reserve funds. (2) National allocation. Special funds allocated by the state to enterprises for special purposes. Including new product trial production fee, intermediate test fee and main scientific research fee. ③ Special loans. In order to complete a special project, enterprises apply for various special loans from banks, including major repair loans and renovation loans, in the case of insufficient special funds. ④ Special accounts payable. Various payables temporarily occupied during the use of special funds. Enterprises using special funds must follow the principles of earmarking, saving before using, living within our means and saving, and strive to improve the use effect of special funds. Take the American fund industry as an example. The common investment fields of specialized funds are high-tech, mass media, health care, finance, public utilities, natural resources and real estate.