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.