The climatological annual cycle of global oxygen anomaly of the upper 0–2000m global ocean is described using gridded monthly dissolved oxygen data of historic observations. The quality controlled dissolved oxygen observation dataset adopted here includes the availabale profiles from the three WOD18 instrumental groups of the ocean station data(OSD) , conductivity temperature-depth(CTD) data and the profiling floats (PFL) data profiles. The largest seasonal changes in oxygen anomaly occur in the extra-tropics region of each hemisphere. The transition between seasonal increases and decreases in the ocean is roughly reversed in the extra-tropical north hemisphere compared with the south hemisphere, as the two hemispheres are nearly six months out of phase. The apparent oxygen utilization is also evaluated to analyze the anuual cycle excluding the impact of the solubility.