The Chinese mitten crab () is a native and important cultured freshwater that is widely distributed in the Yangtze Estuary, China. Many scholars have focused on crab farming, disease prevention, and diet. However, little is known about the feeding rhythm of Chinese mitten crabs, in regards to feeding mode, which is directly related to the feeding time, feeding method, and frequency of feeding strategies, which may affect feed efficiency, as well as aquaculture water. Accordingly, the present study investigated crab feeding behavior under a 24-h photoperiod and, ultimately, established a theoretical basis for determining optimal feeding time, which could benefit large-scale aquaculture and, therefore, improve feed utilization and reduce both water pollution and breeding costs. Crabs with weight of (68.0 ±2.4) g were randomly distributed among 24 cement pools (0.7 m×0.4 m×0.5 m, L×W×H). Each group had three cement pools replicates, each housing 5 crabs, and fed at different time points (10:00, 13:00, 16:00, 19:00, 22:00, 01:00, 04:00, and 07:00). After 10 d, three crabs from each pool were randomly selected and sampled for intestinal and hepatopancreas. The results showed that juvenile crabs exhibited different feeding patterns at different feeding times, and the peak of feeding was observed at 22:00. Based on the average food intake over 6 d, it was clear that the crabs fed primarily at 19:00-22:00. Meanwhile, amylase activity was higher in the hepatopancreas samples of crabs fed at 22:00 than in those of crabs fed at other times (except 19:00). Lipase, alkaline phosphatase, and Na⁺-K⁺-ATPase activities increased from 13:00 to 22:00 and decreased thereafter. Leptin expression in the hepatopancreas of crabs fed at 22:00 p.m. was significantly lower than that of crabs fed at either 13:00 or 16:00, whereas cholecystokinin (CCK) expression was lowest in the intestines of crabs fed at 22:00. In conclusion, feeding of Chinese mitten crab was with an increasing feed intake at 16:00; there after tend to decrease at 22:00. This could be attributed to the visual underdevelopment of the crabs. According to the observed feeding rhythm, Chinese mitten crabs are nocturnal and feed at night. The activities of digestion and absorption enzymes were lowest in crabs fed at 10:00-13:00 and increased from 16:00 to 22:00, with the highest level attained at 22:00. These results could indicate a strong the ability of nutrients digestion and absorption at 22:00. It was consistent with the trend of total feed intake. Digestive and absorption capacity are important indicators of feed utilization and animal growth, and enzyme activity can be used as an indicator of digestive and absorption capacity. On the contrary, the expression of leptin and CCK were downregulated at 22:00. These results were supported by the fact that leptin and CCK are involved in the regulation of food intake. According to previous studies, decreases in leptin and CCK increase the feed intake of animals, which also explains the why, in the present study, the highest feed intake was observed at 22:00. Overall, feeding Chinese mitten crabs at 22:00 could enhance digestion and absorption. Therefore, feeding at 19:00-22:00 could improve feed intake and efficiency.