This paper deals with the application of 1:200,000 regional geochemicar reconnaissance data to agriculture and environment. Specifically, the study tries regionally to solve the problems of crop yields and endemic deseases.Our research work was carried out in Qinglong and (Sanhaignan sheets of Hebei Province. Acomparison of the distribution Pattern between elements in rocks, soils and stream sediments can regionally represent or reflect the fluctuation of elements in soils of the stream catchment. Investigation into the relation of crop yield and death rate in recent years to geochemical distribution of elements reveals that:(1) deficiency of Zn, Mo and Co in large areas of the sheets has to some extent exerted adverse effects on the increase in output of certain crops; (2) the low concentration of Mo in the environment coincides with the distribution of esophagus cancer, and the low concentration of Cr with hypertension and diabetes. Last but not least, it is pointed out that the potential threat of Cd, As and Pb anomalies in the upper reaches of Panjiakou reservoir which supplies drinking water for Tianjin City should be taken into account.According to the comparison and investigation, the normal range as well as the deficiency and excess limits of the elements in these sheets are preliminarily determined, and the environmental geochemical maps of Zn, Cu, Co, Mo and Cr are tentatively compiled.