Complexane-type surfactants possessing two and three alkyl chains (2R_nida, 2R_nedda, 2R_ndtda and 3R_ndtda; n means alkyl chain length) were prepared by the corresponding amine and the appropriate alkyl bromide and examined for surface activity. Critical micelle concentration (cmc) was found to shift to lower concentration with increase in alkyl chain length, number of alkyl chains and decrease in spacer length. Cmcs of 3R₈dtda and 3R₁₂dtda having three alkyl chains were 2-3 smaller than that of the corresponding surfactant having one alkyl chain. Surface tension of complexanes was significantly affected by alkyl chain and spacer length and the number of alkyl chains. Surface tension of 3R₈dtda attained to 24.0mN m^-1 at cmc. Cross-sectional molecular areas of 3R_ndtda with n=6-12 were extremely small in comparison with three times of that of R₁₂NAc and those of 2R_nida, 2R_nedda and 2R_ndtda. Complexane solution was emulsified by shaking with toluene. 2R₁₂ida showed a stable water-in-oil type emulsion and 2R_nedda and 2R_ndtda with n=10-12 and 3R₈dtda each showed a high oil-in-water type emulsion. Interfacial tension between toluene and complexane solution was 1-2mN m^-1 for complexanes with n=12. Multi-alkylated complexanes with HLB of about 22 showed the greatest surface activity. 3R₈dtda was a more efficient surfactant at air/water and toluene/water interfaces.