Defect characterization of Tl2Ga2Se3S single crystals has been performed by thermoluminescence (TL) measurements at low temperatures between 10 and 70K with various heating rate ranging from 0.6 to 1.0K/s. The TL signal due to the luminescence from trap centers revealed one glow peak having maximum temperature of 36K. Curve fitting and various heating rate methods were used for the analysis of the glow curve. The activation energy of 13meV was found by the application of curve fitting method. This practical method also established that the trap center exhibits the characteristics of mixed (general) kinetic order. In addition, various heating rate analysis gave a compatible result (13meV) with curve fitting as the temperature lag effect was taken into consideration. Distribution of traps was also investigated using an experimental method. A quasi-continuous distribution was attributed to the determined trap centers.