Abstract: The Shuangkoushan area of Dachaidan in Qinghai Province is one of arid desert and gobi landscape areas,with the typical climatical characteristics of continental desert.Mainly relying on the project "Qinghai Luliangshan-Shuangkou Shan Mining Vision Survey",we carried out the effective method tests about theoptimum sampling grain size and sampling density to regional geochemical in arid desert and gobi landscape area.Through field sampling,laboratory analysis and data processing,we determined the sampling methods of 1:50000 stream sediment survey for this special landscape area.The reasonable sampling density is 6-8 samples per square kilometer,and the reasonable sampling grain size is-20-+60 mesh.