Two solutions,in one of which Cu²⁺: H₂Sal^*=10:1,and in the other,20:1,were subjected to pH-titrations with μ≈0.03 at 20±0.5℃.The stability constants of CuSal and CuHSal⁺ have been calculated from the results thus obtained by the method of Schwarzenbach.The logarithm of the stability constant of CuSal was found to be 10.5.This figure agrees very well with those obtained by other authors with different methods.The fact that the stability constant of CuHSaI⁺ turned out to be negative would be an indication of the absence of this cation in aqueous solution under the experimental circum- stances.