This paper present the features extraction of the real time voltage signal performed by S-Transform analysis for the purpose of detection and classification of PQ disturbance, which focus on voltage sag, voltage swell and transient. The extracted features will be used as a parameter in detecting and classifying the single and multiple PQ disturbances. As for validation purpose, the real time S-Transform based disturbance analysis is compared with Continuous Wavelet Transform. The result indicate that the S-Transform is more superior and provide more accurate analysis result especially in detection and classification of multiple PQ disturbance.  The analysis of the transformed voltage signal features is conducted in LabVIEW software with the aid of data acquisition module voltage measurement to acquire voltage signal with PQ disturbance generated by Chroma Programming AC Source. In order for the S-transform to provide significant and precise S-matrix features, the real time voltage signal must be acquired with appropriate data acquisition module and adequate sampling rate.