The present study investigated the incomings and outgoings budget of dissolved oxygen (DO) in juvenile Chinese mitten crab (Eriocheir sinensis) culture ponds. The research was conducted in six juvenile crab farming ponds in Maogang Town, Songjiang District, Shanghai from July to October in 2019. The DO production from photosynthesis, respiratory oxygen consumption by Alternanthera philoxeroides, juvenile crab, pond sediment, and oxygen consumption of aquatic respiration were measured. The DO incomings from deploying aerators, and oxygen exchanges between water and atmospheric were calculated based on measured values by the subtraction method. The DO production from photosynthesis was less than the water respiratory oxygen consumption during the test period, only the DO production from photosynthesis in the surface water column was significantly greater than the water respiratory oxygen consumption, and the DO production from photosynthesis in the middle and bottom water layers were almost zero. There was no significant difference in the respiratory oxygen consumption by different water layer. Mechanical aeration was the main factor contributing to the DO incomings, accounted for 72.32% of the total DO incomings; this is followed by oxygen exchanges between water and atmosphere 24.02%, and DO production from photosynthesis 3.66%. Alternanthera philoxeroides is the main factor of DO outgoings, accounting for 80.51% of the total DO outgoings. The respiratory oxygen consumption of Alternanthera philoxeroides is about 21 times that of DO production from photosynthesis. Benthic respiration, juvenile crab respiration and aquatic respiration accounted for 4.19%, 4.81% and 10.49% of total oxygen outgoings, respectively. The results show that in the juvenile crab ponds, regular cleaning of Alternanthera philoxeroides and control of the aerators operating time are important means to maintain the balance of DO.