Aging is a series of complex life processes that occurs in living organisms and usually leads to a series of degenerative manifestations in reproduction, metabolism, stress, and exercise behavior. In this experiment, the model organism zebrafish was used as an experimental animal. The characteristics of 6-month and 30-month zebrafish were distinguished based on the body morphology and reproductive ability, and the circadian rhythm, stress behavior and respiratory metabolism of 6-month and 30-month zebrafish were compared, in order to investigate the effects of aging on metabolism and behavior of zebrafish. The results showed that the spine of 30-month zebrafish was curved and the reproductive performance of old fish was lower than the 6-month zebrafish in terms of fecundity, fertilization rate, hatching rate and survival rate, showing obvious aging characteristics. The swimming behavior of the 6-month zebrafish dispalys an obvious circadian rhythm. Compared with the 30-month zebrafish, 6-month zebrafish is active in the daytime, and always rest at night. The swimming behavior in the daytime and nighttime is significantly different. When 6-month zebrafish suffered from chase-stress, their large movement distance, large movement time and average swimming speed were higher than those of 30-month zebrafish (P<0.05). When exposed to light-stress, the large movement distance and average swimming speed of 6-month zebrafish were higher than those of 30-months zebrafish (P<0.05). The results of stress behavior showed that the stress response ability in aging zebrafish is significantly weaker than that of young zebrafish. The standard metabolic rate (SMR), maximum metabolic rate (MMR), and metabolic space (MS) of 30-month zebrafish were lower than those of 6-month zebrafish (P<0.05), which was consistent with the difference in stressed swimming behavior. Reproduction, metabolism and stress behavior are important physiological activities of fish, and investigating these physiological responses and behaviors in aging and young zebrafish can help to understand the effects of aging on the physiological functions of organism, and furthermore, the molecular mechanism of metabolism and behavior associated with aging.