According to the assessment and the checking and acceptance of some fifty 1:200, 000 regional geochemical prospecting map areas, it is considered that the comparatively low quality shown in a few map areas of MGMR is mainly attributed to the unclear quality requirements and loose management. Based on experience gained by MGMR, the authors have compiled "Quality Evaluation Criteria for Field Sampling, Sample Processing and Firsthand Data in 1:200, 000 Regional Geochemical Prospecting"and "Criteria for Marking Mul tielement Analytical Quality in 1:200, 000 Regional Geochemical Prospecting". Nearly three years’ practice demonstrates that these two sets of criteria are affective in raising the sampling and analytical quality. In this paper, they are given in full text for the sake of reference.