The results of calorimetric study of the Al-Ga system using Oelsen method are presented in this paper. Following thermodynamic parameters were obtained: activities, activity coefficients, partial and integral molar quantities at temperature of 727 degrees C, and compared with available literature data. Also, the energetic of mixing in liquid alloys has been analyzed through the study of concentration fluctuation in the long-wavelength limit. (c) 2012 Elsevier B.V. All rights reserved.