用离子交换平衡法测定了陕西主要土壤土、黑垆土、黄绵土胡敏酸－铜络合物的稳定常数。结果表明：胡敏酸－铜络合物的ｌｏｇＫ呈：黑垆土＞土＞黄绵土的趋势；ｐＨ值从４．０～７．０，ｌｏｇＫ值均递增；离子强度（Ｉ）从０．００～０．１０，温度（Ｔ）从２９８Ｋ～３１３Ｋ，ｌｏｇＫ值均减小；络合反应热力学函数变化△＿ｒＧ￣θ＿ｍ＜０，△＿ｒＨ￣θ＿ｍ＜０，△＿ｒＳ￣θ＿ｍ＜０；配位数（ｘ）为非整数，此络合物属多点位络合。黄绵土胡敏酸－铜络合物具有环境变异稳定性。 The stability constants of humic acid-copper complex in major soils of Loess Plateau, Loess Plateau and Loess were determined by ion exchange equilibrium method. The results showed that the log K of humic acid-copper complex showed the trend of black loess soil> loessial loam soil. The pH value increased from 4.0 to 7.0, and the log K value increased. The ionic strength (I) increased from 0.00 ~ 0.10, the temperature (T) decreased from 298K ~ 313K, the logK value decreased; the thermodynamic function of the complexation reaction △ _rG ~ θ_m <0, △ _rH ~ θ_m <0, △ _rS ~ θ_m <0; (X) is a non-integer, this complex is multi-bit complex. Loess soil humic acid - copper complex with environmental stability variation.