Chemical leaching is widely applied to geochemical research of sediments. In this paper, 1 mol/L hydrochloric solution (HCl) and 1 mol/L acetic acid (HAc) were used to conduct leaching experiments on loess and paleosol samples. HAc leaches mainly the carbonate fraction in the loess and paleosols but has little effect on silicates or iron oxides. In contrast, 1 mol/L HCl solution dissolves not only carbonates but also some of iron oxides and chlorites, as evidenced by higher concentrations of Mg and Fe and higher leaching percentages of elements in the HCl leachate. Experimental results show that 1 mol/L HAc is an ideal dissolvent that caselectively leach the carbonate fraction in the loess and paleosols. On the basis of the leaching results, the average composition of the carbonate fraction, i.e., 1.71% of MgO, 490×10-6 of Sr and 6 7 0×1 0-6of MnO , was obtained . The leaching parameters reflect the degree of pedogenesis of the loess and paleosol sequence; moreover, the MnO content of HAc leachate is the best parameter to indicate the degree of pedogenesis.