In this paper, experimental data on different physicochemical properties of С₆₀[C(COOH)₂]₃ aqueous solutions are presented. Concentration and temperature dependences on density (ρ), viscosity (η), refractive index (n_D), speed of sound (u), surface tension (γ), as well as nanoparticle size dimensions (δ_i) of water solutions were obtained and characterized. The obtained T-x dependences of density, viscosity, refraction index and speed of sound were correlated using fourth-order polynomial equation. Moreover, the solubility diagram of carboxylated fullerene derivative in ternary system С₆₀[C(COOH)₂]₃–NaCl–H₂O at T = 298.15 K was investigated.