The present paper deals with the effect of the components of soils on the specific adsorption of copper ion and its characteristics. Latosol, red earth and paddy soil (neutral) were used in this paper. The specific adsorption of Cu²⁺ ion was determined in the presence of 0.5 M NaCl as supporting electrolyte, and the initial pH of solution was 4.00.The results showed that Cu specific adsorption isotherms of tested soils followed the Langmuir equation (Table 2). The specific adsorption of Cu by latosol and paddy soil was greater than that of red earth. By comparison of maximum adsorption, the specific adsorbed Cu of latosol and paddy soil was about 3.1 times and 3.0 times the amount of adsorbed Cu of red earth respectively.Desorption experiments reveled that there existed two types of specific adsorbed Cu, one was with a low bonding energy and could be desorbed by 1 N NH₄Cl (pH 5.0) and the other was with a high bonding energy and could only be desorbed by 0.1 N HCl, corresponding to the loosely bonding and tightly bonding fractions of copper respectively.The tightly bonding Cu was independent of the concentration of Cu added, once the specific sites were filled with this fraction of copper (Fig. 3, 4, 5), it had greater affinity with the specific sites. The loosely bonding Cu increased with increasing concentration of copper added, and followed the Langmuir equation (Fig. 3, 4, 5). Thus there must be a fixed number of specific sites at a given pH from which copper is less readily desorbed (tightly bonding Cu), and with increasing concentration of copper added, there will be an increasing proportion of the adsorbed Cu at that pH which can be readily desorbed (loosely bonding Cu).At lower concentration of copper added, tightly bonding Cu was more than loosely bonding Cu for latosol and paddy soil, and vice versa. Loosely bonding Cu dominated in specific adsorbed Cu for red earth. The amount of tightly bonding Cu in soils was in the order: latosol>paddy soil>red earth; while that of loosely bonding Cu in soils was in the order: paddy soil>latosol>red earth. This distinct difference in specific adsorbed Cu for the tested coils is probably related to the different content and properties of hydrous oxides, organic matter and composition of clay minerals of soils.