Abstract: Seven-six floodplain sediment samples from Sichuan,Yunnan,Guizhou,and Guangxi were an-alyzed by eight labs to explore a more effective approach to the appraisal of analytical quality in order to select the best analytical methods for the compilation of geochemical atlas of 76elements in Sichuan,Yunnan,Guizhou,and Guangxi.An appraisal of analytic data of Ag was made by using reference values,statistical parameters,similarity coefficients,density distribution functions ,the space structure of the geo-chemical fields,and overlapping of geochemical anomalies.It is not only required that the absolute values of the analytic data should be precise to a certain degree,but the spatial attribute of the geochemical data is also emphasized.Furthermore,it is also required that the spatial distribution of the analytic data should agree as well as possible with the ideal geochemical maps.