Soil evidence is one of the main research subjects in forensic science.In this paper,18 soil samples from different regions were tested and analyzed together with the screened clays from those samples by the thermal gravity(TG)approach.The content variation of organic constituents was studied along with the thermal characteristics of minerals from the samples.The results show that the soils' both TG and DTA(differential thermal analysis) curves display their own difference at the quantity and so do the rate...