Erucyl amidopropyl carboxyl betaine EBC was prepared from erucic acid, N,N-dimethyl-1,3-propanediamine, and sodium chloroacetate. The structures of erucyl amide EA and betaine product EBC were analyzed by FTIR and MS. Surface/Interface activities, adsorption characteristic and viscosifying capability of this surfactant were evaluated. The CMC of betaine EBC was 1.02×10-5 mol/L, and corresponding γCMC was 29.60 mN/m. The minimum carbon number of this betaine was 16. At alkali-free condition, ultralow interfacial tensions in the 10-4~10-3 mN/m magnitude were reached for betaine EBC with crude oil of Daqing and Sudan oilfields. In content range of 0.001%-0.20%, interfacial tension between EBC/DABS(8:2,wt%/wt%) combined formulation and crude oil of Changqing oilfield reached ultralow magnitude, showing excellent interfacial activity and strong anti-dilution capability. The adsorption on natural core sand of EBC was in 0.07~0.51 mg/g sand range, less than 1.0 mg/g evaluation criteria. In addition, solutions of this betaine exhibited good viscosifying capability. Erucyl amidopropyl carboxyl betaine EBC can be used as a suitable oil-displacement surfactant in combined chemical flooding.