Abstract: ASP flooding water contain a large number of agent such as polymers 、 surfactants and alkaline which will make water quality extremely complex and increase oil-water stability significantly,these all make treatment more difficult. The influences of polymers,surfactants and alkaline on oilwater separation have been analyzed.Results indicate that with the increase of polymer concentration,Zeta oil droplets electro negativity increases,the viscosity of water increase which slows oil-water separation and increases settlement time ; the synergy between surfactants and polymers can enhance oil content greatly,and the synergy between surfactants and alkaline can reduce oil-water interfacial tension greatly ; surfactants from reaction between alkali and acid in crude oil can increase oil content in water.