Abstract:A soil sample submerged in water previously was saturated with Cu++ by 1 N CuCl2, and its cation exchange capacity was then determined by leaching with 1 N NH4Cl. However, the eation exchange capacity obtained was always lower than untreated samples. This indicated that certain amounts of Cu++ were attracted by exchange site. The △ valve of CEC showed a well positive correlation with dithionite-citrate soluble Fe2O3 and clay content of the soil samples used in present experiment. (r2=0.51 for Fe and r2=0.64 for clay; n=25).The total amount of fined Cu++, including a part of complexed form was determined eolorimetrically in the same extracting solution used for CEC measurement of soils treated with Cu++. It was showed that there is not any correlation between the total amount of fixed Cu++ and the organic matter or clay content of the samples. However, the difference between the amount of fixed Cu++ and △ value of CEC was correlated with the organic matter content and C/N ratio of soils.