Mystus macropterus (Bleeker) is a freshwater fish of the Bagrdae family, distributed in the main stream and tributaries of the Yangtze and Pearl rivers with high nutritional value. The author found that M. macropterus displayed aggressive behavior, which led to bites, ulcers, and even death during artificial breeding. Understanding the behavioral characteristics of M. macropterus and its influencing factors and reducing its aggression would help understand the basis of artificial breeding. In the present study, a real-time observation system incorporating indoor pools, cameras, transmitters, and monitors was established to observe the behavioral characteristics of M. macropterus. At the same time, three kinds of caves (tiled, pebble and grass caves) were established in all breeding pools. M. macropterus were divided into three groups based on the proportion of the fish and caves which were free choice group (1 fish), competition-absent group (3 fish), and competition-present group (6 fish). The selection of M. macropterus to shelters under three conditions was recorded by video. The recording started when the fish were put in, and each recording lasted for 72 hours, and all experiments were conducted in triplicate. The results showed that M. macropterus preferred tiled and pebble caves. Not many fish coexisted peacefully in these two caves, but two fish coexisted in grass caves. The attack frequency in the competition-present group was significantly higher than that in the competition-absent group, and the attack frequency at night was significantly higher than that during the day. M. macropterus hid in caves during the day and came out at night. The behaviors included daily activities, such as exploration, patrol, and hunting; attacking behaviors, such as chasing, collision, and biting; and territorial behaviors, such as invasion, driving, and guarding. Social hierarchies were established based on aggression, labeled “strong” and “weak.” The behavioral characteristics of M. macropterus and the selection of hiding places provided an important scientific basis for establishing M. macropterus farming technology. It was suggested that the strategy of night feeding should be adopted in M. Macropterus culture, and an open shelter should be built in the pond for hiding.