An equation of state (EOS) applicable to both the uniform and non-uniform fluid was established using the second-order perturbation theory, the Duh-Mier-Y-Teran EOS and the direct correlation function obtained by mean spherical approximation (MSA). The phase equilibrium and the surface tension for Yukawa fluid were studied by combining the EOS, the renormalization group (RG) theory and the density functional theory (DFT). The results agree well with the simulation data.

Key words: Yukawa fluid, direct correlation function, phase equilibrium, surface tension, renormalization group theory, density functional theory