Abstract: The spatial and temporal variations in surface dissolved oxygen (DO) in the Yellow Sea during different periods were investigated based on DO data obtained from in-situ measurements made during year of 1960~1997.The results showed that:the monthly variations of surface DO in different periods exhibited similar trends, with the maximum (6.73 mL/L) and minimum (4.90 mL/L) values occurring in March and August, respectively; the seasonal variations during different periods all followed the order Spring > Winter > Summer > Autumn.The annual variation in surface DO presented stable trend over the duration of the entire period.Spatial distribution of the surface DO also presented obvious seasonal variations; there was a decreasing trend from the western coastal waters to the east open sea and an increasing trend from southern to northern.The mean values and spatial distributions were similar in Winter and Spring due to the effects of the Yellow Sea warm currents, while in Summer and Autumn they were similar due to solar radiation and water circulation in the sea.The surface DO was negatively correlated with the surface sea temperature.However, it increased with the nutrient levels (PO₄-P、NO₃-N and SiO₃-Si).The mean apparent oxygen utilization (AOU) was-0.06 mL/L, which indicated that the AOU kept balance during the study period.