Na(x)Nd((2-x)/3)TiO(3) solid solutions possess tetragonal or orthorhombic perovskite structure, where the A-sites are characterized by 2 kinds of cations (Na(+), Nd(3+)) and vacancies. We have measured microwave dielectric properties of Na(x)Nd((2-x)/3)TiO(3) solid solutions (x = 0.05 to 0.5) to investigate an effect of the compositional ordering in the A-sites of the perovskite structure. According to powder x-ray diffraction, the A-site is disordered in the composition range of x = 0.29 to 0.5. A compositional ordering (Na(+), vacancy / Nd(3+)) in A-sites appeared when x = 0.05 to 0.2. The quality factor (Q x f), where Q is the inverse of dielectric loss and f is frequency, was found to be slightly improved with decreasing Na content in the range of x = 0.05 to 0.2, suggesting that the Q x f of the Na(x)Nd((2-x)/3)TiO(3) solid solutions depends on the compositional ordering in A-sites.