The impact of O2 plasma treatment on novel amorphous oxide InWZnO (IWZO) as conductive bridge random access memory (CBRAM) was investigated. A high-quality film on the surface of IWZO can be obtained by using remote O2 plasma treatment. The uniformity of O2 plasma sample is better than control sample, and also the set and reset voltage are more uniform and smaller to suitable for memory operation. Moreover, the O2 plasma sample shows excellent memory performance, such as high switching endurance cycles (up to 3 × 103), long retention time for 104 s at 85 °C. These results show that the surface modification with O2 plasma on IWZO CBRAM device is a critical technique for next generation memory applications.