The environment benchmark is not only the scientific basis of environment standard, but also the scientific fundaments of environmental quality assessment, risk control, emergency management and the whole environmental management system. Therefore, it is the cornerstone of national environmental protection and environmental management. China is a major agricultural country and heavily populated, where the food production is the strategic basis of national security. Therefore, it is very important to set up reliable soil environmental standard and to guarantee food safety. In this research, results of field sample analysis，pot experiment and isotopic finger print study will be combined with literature findings to provide scientific basis for a more reliable environmental standard of heavy metals in agricultural fields.