To investigate the effects of fasting on maximum metabolism, hypoxia tolerance and heat tolerance of goldfish (Carassius auratus), experimental goldfish were randomly divided into normal feeding control group and fasting group for 14 days. The maximum metabolic rate (MMR), critical oxygen pressure (Pcrit ), loss of equilibrium point (LOE), critical high temperature (T max C), lethal high temperature (T max L), critical low temperature (T min C), and lethal low temperature (T min L) were measured, and the critical metabolic rate (CMR) was calculated. The results showed that: compared with the control group, the MMR of fasting group was significantly increased (p<0.05). In hypoxic tolerance, the difference of Pcrit and LOE between treatment group and control group was not statistically significant, but the CMR of fasting group was significantly decreased compared with that of control group (p<0.05). In the heat tolerance experiment, compared with the control group, the T max C and T max L of the fasting group was decreased while the T min C and T min L of the fasting group was increased, and the differences of the four indices among the groups were statistically significant (p<0.05). These results indicated that the MMR and hypoxia tolerance of goldfish increased significantly after short-term fasting, while the high and low temperature tolerance of the species decreased significantly.