We have used simple statistical model to report the energetic and its effect on the alloying behavior of Bi-Sn and Bi-In liquid alloys. The energetic of mixing in liquid alloys has been analyzed through the study of bulk and surface properties. In the bulk, we have studied thermodynamic properties, which include Gibb’s free energy of mixing, enthalpy of mixing and entropy of mixing. The surface behavior has been analyzed by computing surface concentration and surface tension of the alloys. For the microscopic structural investigation our study includes concentration-concentration fluctuation in long wavelength limit and Warren-Cowley short range order parameter, they have been discussed in term of the energetic of the bulk as well as that of the surface part. The computed results are in good agreement with experimental data and support a weak phase-separation tendency in molten Bi-Sn system and ordering behavior in Bi-In system. In both system, temperature dependent energy parameter takes important role to explain bulk and surface properties.