Densities of LiB5O6(OH)(4)(aq) at molalities of 0.09859-0.89493 mol.kg(-1) were measured at 5 K intervals from 283.15 to 363.15 K at 101.325 kPa using a precise Anton Paar Digital vibrating-tube densimeter. The apparent molar volumes (V-phi), thermal expansion coefficients (alpha), and partial molar volumes ((V) over bar (B)) were obtained. On the basis of experimental data, diagrams of the thermodynamic parameters (alpha, V-phi, and (V) over bar (B)) against molality at different temperatures were plotted. According to the Pitzer model of apparent molar volume, the Pitzer parameters (V) over bar (B), beta((0)v,)(M,X) beta((1)v)(M,X), beta(M,X) ((2)v), C-M,X(v), and the coefficients a(i) of the temperature-dependence formula f(i, p, = a(1) + a(2) ln(T/298.15) + a(3)(T 298.15) + a(4)/(620 + a(5)(T - 227) (where T is the temperature in Kelvin) for LiB5O6(OH)(4) were fitted by the least-squares method. The predictive apparent molar volumes agree well with the experimental values, and those results indicated that the single salt parameters and the temperature-dependence formula are reliable.