To investigate the effects of thermal stratification and eutrophication on dissolved oxygen, seasonal variations and vertical distribution of water temperature, dissolved oxygen, chlorophyll a and primary production were monitored from January 2014 to December 2014 in the Zhoucun Reservoir. The results showed that water temperature and dissolved oxygen both experienced stratification from April to November. The chlorophyll a was 20~50μg/L, the primary productivity was 2.16~2.23g O₂/(m×d) and the position of light compensation point was between 1m and 3m during stratification. The hypolimnion has been in anaerobic condition since mid-May. Because of the high position of light compensation point, the oxycline's position was between 1m and 6m during stratification, higher than thermocline's. The maximum value of dissolved oxygen was usually at the surface since the position of oxycline was high and the dissolved oxygen gradient was large in the empilimnion. The vertical migration of thermocline made oxycline and anaerobic zone interface both moved down between September and November. The anaerobic zone interface' position was always the same as thermocline's, while the oxycline would move up again when the thermal structure was relatively stable. The thermal stratification and eutrophication have significant effects on dissolved oxygen concentration and distribution.