In bi-layer structural ReRAM, resistive switching behaviors strongly depend on condition of interfacial layer between oxygen absorption layer and active layer. The condition of interfacial layer is investigated to improve the resistive switching behaviors of bi-layer structural ReRAM. By changing deposition ambient of the oxygen absorption layer, in low power operation, more stable and larger on/off ratio were achieved. Based on the results of electrical and physical analyses, the oxygen content difference of active layer is considered as a dominant origin.