Abstract: A new kind of cationic trisiloxane surfactant (CTSS) was synthesized by the ring-opening reaction of polyether epoxy group trisiloxane (PEETS) with diethanolamine. PEETS was prepared by hydrosilylation from 1,1,1,3,5,5,5-heptamethyltrisiloxane (MDHM) and allyl polyoxyalkylene glycidol ether (APEE) in the presence of platinum catalyst. The chemical structure of CTSS was characterized by IR and 1H-NMR. The interfacial properties of CTSS were mensurated. Experimental results showed as follows. The yields of PEETS and CTSS are 90.6% (based on MDHM and APEE) and 91.8% (based on PEETS and DEA), respectively. The viscosity and refractive index of CTSS are 2 600 mPa•s and 1.4742, respectively. In the critical micelle concentration of 8.7×10-4 mol•L-1, the surface tension of CTSS aqueous solution reduced to approximately 25.8 mN•m-1. The saturated adsorption, single CTSS average areas on saturated absorption layer and micellization standard free energies are 4.9×10-6 mol•m-2, 0.34 nm2 and -27.4 kJ•mol-1, respectively.