Abstract: Using anion-surfactant SDS as an aid-surfactant to study the affecting of anion-surfactant SDS to flooding recovery properties under DC electrical field. It was found that the flooding recovery increased by adding as in brine under electric field, and it was 4% higher than simple DC electrical field. Also in the residual oil period, the final recovery was increased 6%. The sequence of increasing recovery magnitude is:general flooding,surfactant flooding,DC electric field flooding and DC electric field flooding with aid-surfactant.