Nonylphenol polyethoxylate (NPEOn) has been expected to enhance salt tolerance of system containingcarboxylates, but banned in countries recently. Herein, a group of new surfactants, nonylcyclohexanolpolyethoxylate (NCEOn) was formulated with sodium oleate (NaOA) into binary surfactant systems, toinvestigate their interaction towards salt tolerance, phase behavior, interface tension and lime soap dispersingrequirement in brine with comparison of NPEO10. The results indicate that the salt tolerance ofNaOA-NCEOn system increased with increasing NCEOn concentration and EO number, following the ordertowards the salts: SO42- > Cl- for anions and Na+ > Mg2+ > Ca2+ for cations, respectively. Moreover, cloudpoint (CP) of NaOA-NCEOn system was increased by adding NaOA but decreased by introducing inorganicsalts, respectively. The influence strength of cationic ions on CP decline was in the order: Na+ < Mg2+