An equation of state (EOS) applicable for both the uniform and nonuniform fluids is established by using thedensity-gradient theory (DGT). In the bulk phases, the EOS reduces to statistical associating fluid theory(SAFT). By combining the EOS with the renormalization group theory (RGT), the vapor−liquid-phaseequilibria and surface tensions for 10 nonpolar chainlike fluids are investigated from low temperature up tothe critical point. The obtained results agree well with the experimental data.