Bola amphiphiles (ArN-n-NAr, n = 4, 6, 8, 10) with quaternary ammonium headgroups have been synthesized. Results show considerable enhancement in the efficiency (C20) and the effectiveness (cmc) in surface tension reduction as well as the ability of micelle formation (cmc) in the mixed aqueous solutions. The minimum C20 value (0.076 mmol/L(n=4), 0.048 mmol/L(n=6), 0.046 mmol/L(n=8) and 0.026 mmol/L(n=10)) was obtained at 1=0.33 (1 represents the molar fraction of ArN-n-NAr) in the mixed aqueous solution. Compared with the pure SDS solution, the cmc of the mixed systems show significant decrease. For the ArN-10-NAr/SDS system, the cmc was decreased more than 9 times (from 2.40 mmol/L to 0.26 mmol/L). The length of ArN-n-NAr spacer in mixed solution was 0.635 nm (n=4), 0.889 nm (n=6), 1.143 nm (n=8) and 1.397 nm (n=10). The outer surface of the mixed adsorption layer at the air/water interface was totally composed by SDS while ArN-n-NAr was arranged at the sublayer neighboring the outside. The ArN-n-NAr molecules adopted lying (for n=4, 6, 8) or perpendicular (for n=10) pattern according to the spacer length between the two headgroups of Bola amphiphiles.