Abstract: Field ecosystem can produce ecosystem services and economic production with the annual total value of 1950910 million yuan tO human beings contributed by natural and anthropogenic process．In the total value supported by food pro-duction，41.9％ is supplied by natural process and 58．1％ is contributed by human activities ，such as seeding，planting，ir-rigating and SO on．However，only the economic value supported by human activities and part of the ecosystem services by natural process are computed which iS 64.7％ of the total value and the rest 35.3％ of total value iS not calculated in the conventional calculation of annual output by plantation which is 688106 million yuan．According to these data，the highestlevel of public financial allowance supported by the government to food prod uction can be 5140 yuan／hm²·a．due to the public services supplied by plantation in the process of food prod uction．