The significant structure theory of liquids has been successfully applied to liquid gallium. The volume and temperature dependence of the solid-like structure has been properly taken into account in calculations of the thermodynamic and transport properties of liquid gallium. In this study, we have assumed that two structures exist simultaneously in liquid gallium. One is considered as loosely close packed structure, and the other is the remainder of solid lattice. This two-structural model is introduced to construct the liquid partition function. Using this partition function, the thermodynamic and transport properties of liquid gallium are calculated over a wide temperature range. The calculated results are quite satisfactory when compared with the experimental data.