The protonation constant values of different four t riazole derivatives have been determined in ethanol %50 – water %50 mixtures by spectrophotomet ric methods. The electronic absorption spectra of different four triazole derivatives at v arious pH values at 190-400 nm intervals were recorded. The calibration of the electrode system w as done potentiometrically by Gran’s method. Data were calculated using the linearizatio n method with Henderson-Hasselbach equation. The obtained results are in good accordan ce with potentiometric values.